Add swap files and rdoc output to gitignore
Add swap files and rdoc output to gitignore

gavv/rdoc-generator-singlepage,rbdoc/rdoc-generator-singlepage,rbdoc/rdoc-generator-solarfish,rbdoc/rdoc-generator-solarfish,rbdoc/rdoc-generator-singlepage,gavv/rdoc-generator-singlepage