Improvements and some bug fixes

• improvement: raise exception when a route has duplicate params 025d60f
• fix(response): set content-type when unable to stream file e4fcc8d
• chore: update dependencies b4bee00
• style: fix styling of heading comments cb6ba31
• chore: copy jsdoc to typings to enable them inside intellisense 5401de0
• style: fix styling of nearly all comments f9378b7

v2.1.1...v2.1.2