Ignore Docusaurus, build, node_modules, .claude

Update .gitignore to exclude Docusaurus output (/ .docusaurus), build artifacts (/build), node_modules, and the /.claude directory to prevent committing generated files and dependencies.

Author: alegauss

.gitignore

@@ -6,3 +6,7 @@ vendor
 *.pdf
 !presentation.pdf
 /.idea/
+/.docusaurus
+/build
+/node_modules
+/.claude