Provide contributions guidelines via CONTRIBUTING.md file
Merge pull request #2022 from excilys/contributing.md

Provide contributions guidelines
Fix a HeadersValues constant name
Fix build
Upgrade AHC 1.9.0-BETA3
transferEncoding was dropped
Drop type aliases that just bring confusion
Document response processor
minor clean up
Don't discard chunks when a response transformer is set, close #2026
Upgrade AHC 1.9.0-BETA4, close #2027
transferEncoding strikes back
Provide disableChunkDiscarding at request level, close #2028
Documentation review + add contrib guidelines, close #2000, close #2001
Merge pull request #2029 from excilys/doc-review

Documentation review + add contrib guidelines, close #2000, close #2001
Remove unused statsTsvSeparator config option
HttpClientCodec config wasn't passed
Stop using HdrHistogram to compute std dev, close #2030
No need to compute the count
Drop HdrHistogram, only use t-digest, close #2031