readme: add settings for Prettier html formatting

Author: raduweiss

README.md

@@ -3,3 +3,29 @@ This is the presentation website for
 
 We take pull request for content and FAQ improvements, as well as additons to
 the list of Firecracker integrations.
+
+When contributing to HTML pages in this repo, please format the entire file
+with the latest stable [Prettier](https://prettier.io/) release, using the
+settings below for the HTML parser.
+
+```json
+{
+  "arrowParens": "always",
+  "bracketSpacing": true,
+  "embeddedLanguageFormatting": "auto",
+  "htmlWhitespaceSensitivity": "ignore",
+  "insertPragma": false,
+  "jsxBracketSameLine": false,
+  "jsxSingleQuote": false,
+  "printWidth": 120,
+  "proseWrap": "preserve",
+  "quoteProps": "as-needed",
+  "requirePragma": false,
+  "semi": true,
+  "singleQuote": false,
+  "tabWidth": 2,
+  "trailingComma": "es5",
+  "useTabs": false,
+  "vueIndentScriptAndStyle": false
+}
+```