Basic HTTP servers (#2) and various improvements over docs.

CONTRIBUTING.md

@@ -33,6 +33,10 @@ This badge could place only people that present in [maintainers list](MAINTAINER
 
 ## Code
 
+### Before you start contributing code
+
+Please fill bug report or feature request first. Pull requests without filled issue won't be accepted.
+
 ### Linting
 
 Please use [golangci-lint](https://golangci-lint.run/) with configuration from this repository.
@@ -46,3 +50,5 @@ Featurer uses next branching agreement:
 1. `main` branch is a subject of constant changes.
 2. Fork repository, make changes, create pull request.
 3. Releases are cut from release branches named `release/MAJOR.MINOR`.
+
+These agreement will be enforced after first contributor appears! :).