Add installation instructions to LSP plugin READMEs

Each README now includes:
- Supported file extensions
- Installation commands for different platforms/package managers
- Links to project websites and documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

plugins/jdtls-lsp/README.md

@@ -1,8 +1,33 @@
 # jdtls-lsp
 
-This plugin provides LSP (Language Server Protocol) integration for Claude Code.
+Java language server (Eclipse JDT.LS) for Claude Code, providing code intelligence and refactoring.
+
+## Supported Extensions
+`.java`
+
+## Installation
+
+### Via Homebrew (macOS)
+```bash
+brew install jdtls
+```
+
+### Via package manager (Linux)
+```bash
+# Arch Linux (AUR)
+yay -S jdtls
+
+# Other distros: manual installation required
+```
+
+### Manual Installation
+1. Download from [Eclipse JDT.LS releases](https://download.eclipse.org/jdtls/snapshots/)
+2. Extract to a directory (e.g., `~/.local/share/jdtls`)
+3. Create a wrapper script named `jdtls` in your PATH
 
 ## Requirements
+- Java 17 or later (JDK, not just JRE)
 
-The corresponding language server must be installed on your system. The plugin will be recommended when you edit files with the supported extensions and have the language server binary available.
-
+## More Information
+- [Eclipse JDT.LS GitHub](https://github.com/eclipse-jdtls/eclipse.jdt.ls)
+- [VSCode Java Extension](https://github.com/redhat-developer/vscode-java) (uses JDT.LS)