Fix tea comment docs: replace heredoc with quoted strings

Heredoc syntax causes tea comment to be backgrounded and fail silently.
Updated Comments section to:
- Use quoted strings with literal newlines for multiline comments
- Add warning about avoiding heredoc syntax

Closes #10

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/gitea/SKILL.md

@@ -119,15 +119,15 @@ tea clone <owner>/<repo>             # Clone repository
 tea comment <number> "<comment body>"
 tea comment 3 "LGTM, ready to merge"
 
-# Multiline comments (use heredoc)
-tea comment 3 "$(cat <<'EOF'
-## Review Summary
+# Multiline comments (use quoted strings with literal newlines)
+tea comment 3 "## Review Summary
+
 - Code looks good
-- Tests pass
-EOF
-)"
+- Tests pass"
 ```
 
+> **Warning**: Do not use heredoc syntax `$(cat <<'EOF'...EOF)` with `tea comment` - it causes the command to be backgrounded and fail silently.
+
 ### Notifications
 
 ```bash