Add definitions for extra keys in national layouts

The new files Keyboard_{de_DE,es_ES,fr_FR,it_IT}.h add macro definitions
for keys that could not be otherwise easily accessed with the library,
such as "e with grave accent" in the French and Italian layouts.

Only keys that produce either a non-ASCII character or a dead accent
when used unmodified are listed. For instance, the "pound sign" is not
listed in the Italian layout because, without the Shift modifier, that
key prints a "3". The macros are named after the character produced by
the unmodified key. For example, they key for the inverted exclamation
and question marks in the Spanish layout is named
`KEY_INVERTED_EXCLAMATION'.

This mimics what has already been done for the Danish and Swedish
layouts.

Author: edgar-bonet

src/Keyboard_de_DE.h

@@ -0,0 +1,45 @@
+/*
+  Keyboard_de_DE.h
+
+  Copyright (c) 2022, Edgar Bonet
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef KEYBOARD_DE_DE_h
+#define KEYBOARD_DE_DE_h
+
+#include "HID.h"
+
+#if !defined(_USING_HID)
+
+#warning "Using legacy HID core (non pluggable)"
+
+#else
+
+//================================================================================
+//================================================================================
+//  Keyboard
+
+// de_DE keys
+#define KEY_CIRCUMFLEX    (136+0x35)
+#define KEY_ESZETT        (136+0x2d)
+#define KEY_ACUTE         (136+0x2e)
+#define KEY_U_UMLAUT      (136+0x2f)
+#define KEY_O_UMLAUT      (136+0x33)
+#define KEY_A_UMLAUT      (136+0x34)
+
+#endif
+#endif

src/Keyboard_es_ES.h

@@ -0,0 +1,45 @@
+/*
+  Keyboard_es_ES.h
+
+  Copyright (c) 2022, Edgar Bonet
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef KEYBOARD_ES_ES_h
+#define KEYBOARD_ES_ES_h
+
+#include "HID.h"
+
+#if !defined(_USING_HID)
+
+#warning "Using legacy HID core (non pluggable)"
+
+#else
+
+//================================================================================
+//================================================================================
+//  Keyboard
+
+// es_ES keys
+#define KEY_MASCULINE_ORDINAL    (136+0x35)
+#define KEY_INVERTED_EXCLAMATION (136+0x2e)
+#define KEY_GRAVE                (136+0x2f)
+#define KEY_N_TILDE              (136+0x33)
+#define KEY_ACUTE                (136+0x34)
+#define KEY_C_CEDILLA            (136+0x31)
+
+#endif
+#endif

src/Keyboard_fr_FR.h

@@ -0,0 +1,46 @@
+/*
+  Keyboard_fr_FR.h
+
+  Copyright (c) 2022, Edgar Bonet
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef KEYBOARD_FR_FR_h
+#define KEYBOARD_FR_FR_h
+
+#include "HID.h"
+
+#if !defined(_USING_HID)
+
+#warning "Using legacy HID core (non pluggable)"
+
+#else
+
+//================================================================================
+//================================================================================
+//  Keyboard
+
+// fr_FR keys
+#define KEY_SUPERSCRIPT_TWO (136+0x35)
+#define KEY_E_ACUTE         (136+0x1f)
+#define KEY_E_GRAVE         (136+0x24)
+#define KEY_C_CEDILLA       (136+0x26)
+#define KEY_A_GRAVE         (136+0x27)
+#define KEY_CIRCUMFLEX      (136+0x2f)
+#define KEY_U_GRAVE         (136+0x34)
+
+#endif
+#endif

src/Keyboard_it_IT.h

@@ -0,0 +1,44 @@
+/*
+  Keyboard_it_IT.h
+
+  Copyright (c) 2022, Edgar Bonet
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef KEYBOARD_IT_IT_h
+#define KEYBOARD_IT_IT_h
+
+#include "HID.h"
+
+#if !defined(_USING_HID)
+
+#warning "Using legacy HID core (non pluggable)"
+
+#else
+
+//================================================================================
+//================================================================================
+//  Keyboard
+
+// it_IT keys
+#define KEY_I_GRAVE       (136+0x2e)
+#define KEY_E_GRAVE       (136+0x2f)
+#define KEY_O_GRAVE       (136+0x33)
+#define KEY_A_GRAVE       (136+0x34)
+#define KEY_U_GRAVE       (136+0x31)
+
+#endif
+#endif