docs: add documentation for newly added feature

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added handle argument for `ls` to allow listing a specific handle tree. ([#44](https://github.com/EduardoRodriguesF/quartz/issues/44))
 - `quartz use -` to switch to the last used handle. ([#45](https://github.com/EduardoRodriguesF/quartz/issues/45) by [@GabrielBrandao1618](https://github.com/GabrielBrandao1618))
 - Content-type hints `body edit` into correct extension. ([#46](https://github.com/EduardoRodriguesF/quartz/issues/46))
+- Environments can have headers that'll be used by endpoints, unless overriden. ([#43](https://github.com/EduardoRodriguesF/quartz/issues/43) by [@GabrielBrandao1618](https://github.com/GabrielBrandao1618))
 
 ### Fixed
 

doc/quartz.1.md

@@ -310,6 +310,13 @@ To manage environment variables, see *variable* command.
 **env rm** <*ENV*>
 : Delete an environment.
 
+**env header** <*COMMAND*>
+: Environment default header.
+
+    Default headers will be used for every request, unless they are overwritten by endpoint headers.
+
+    Commands are the same as **header** command. See **HEADER** section for more information.
+
 ## VAR
 Manage current environment's variables.