[README] Add community calendar link to the main README (#1662)

Adding the SK Community calendar to the main README for office hours and
community events

### Motivation and Context
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### Description
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### Contribution Checklist
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- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows SK Contribution Guidelines
(https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
- [ ] The code follows the .NET coding conventions
(https://learn.microsoft.com/dotnet/csharp/fundamentals/coding-style/coding-conventions)
verified with `dotnet format`
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

---------

Co-authored-by: Alex Chao <achao@achao>
Co-authored-by: Shawn Callegari <36091529+shawncal@users.noreply.github.com>

Author: 3 people

COMMUNITY.md

@@ -0,0 +1,27 @@
+# Welcome to the Semantic Kernel Community!
+
+Below are some ways that you can get involved in the SK Community.
+
+## Engage on Github
+
+File issues, submit PRs, and provide feedback and ideas to what you'd like to see from the Semantic Kernel.
+We do our best to respond to each submission.
+
+## Public Community Office Hours
+
+We regularly have Community Office Hours that are open to the **public** to join. 
+
+Add Semantic Kernel events to your calendar: download the [calendar.ics](https://aka.ms/sk-community-calendar) file.
+
+To keep topics organized, please submit what you'd like us to cover here:
+[https://forms.office.com/r/BbXFzmmFys](https://forms.office.com/r/BbXFzmmFys)
+
+If you are unable to make it live, all meetings will be recorded and posted online.
+
+## Join the conversation on Discord
+
+We have a growing and active channel on Discord where you can get help, engage in lively discussion,
+and share what you've built with Semantic Kernel!
+
+Join our Discord:
+[https://aka.ms/SKDiscord](https://aka.ms/SKDiscord) 

README.md

@@ -130,6 +130,7 @@ To learn more and get started:
 - Read the [documentation](https://aka.ms/sk/learn)
 - Learn how to [contribute](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md) to the project
 - Join the [Discord community](https://aka.ms/SKDiscord)
+- Attend [regular office hours and SK community events](COMMUNITY.md)
 - Follow the team on our [blog](https://aka.ms/sk/blog)
 
 ## Code of Conduct