Add module documentation and enhance Dokka configuration (#261)

##  #252 Add module documentation and enhance Dokka configuration

## How Has This Been Tested?

`./gradlew :docs:dokkaGenerate`

## Changes

- Add workflow to build and publish API documentation with Dokka
- Introduce `.github/workflows/apidocs.yaml` to build and deploy API
docs on `main` and release events.
  - Configure Gradle for Dokka builds and update project dependencies.
  - Include `:docs` module in project settings.
- Introduce `Module.md` for `kotlin-sdk-server`, `kotlin-sdk-client`,
and `kotlin-sdk-core` modules.
- Update `.gitignore` to include `.idea/icon.png` and add placeholder
icon files
- Remove outdated documentation HTML files

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [x] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Co-authored-by: devcrocod <devcrocod@gmail.com>

kotlin-sdk-core/Module.md

@@ -0,0 +1,5 @@
+# Module kotlin-sdk-core
+
+The MCP Kotlin SDK Core module provides fundamental functionality for interacting with Model Context Protocol (MCP).
+This module serves as the foundation for building MCP-enabled applications in Kotlin.
+