docs: introduce conventional-commits (#1234)

COMMITS.md

@@ -0,0 +1,29 @@
+# Commits
+
+Using [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) is strongly recommended and might be enforced in future.
+
+### Examples
+
+```
+docs: correct spelling of CHANGELOG
+feat: allow provided config object to extend other configs
+feat(lang): added polish language
+```
+
+### Git hook
+
+Use this git hook to auto-check your commit messages. Save the following snippet into `.git/hooks/commit-msg`
+
+```
+#!/bin/sh
+if ! grep -qE "^(build|ci|docs|feat|fix|perf|refactor|style|test|chore|revert)(\((common|core|crypto|legacy|python|storage|tools|vendor)\))?: " "$1" ; then
+  echo "Conventional Commits validation failed"
+  exit 1
+fi
+```
+
+If you want to bypass commit-msg hook check, you may always use
+
+```
+git commit -m "foobar" --no-verify
+```

README.md

@@ -23,6 +23,8 @@
 
 See [CONTRIBUTING.md](docs/misc/contributing.md).
 
+Using [Conventional Commits](COMMITS.md) is strongly recommended and might be enforced in future.
+
 Also please have a look at the docs, either in the `docs` folder or at  [docs.trezor.io](https://docs.trezor.io) before contributing. The [misc](docs/misc/index.md) chapter should be read in particular because it contains some useful assorted knowledge.
 
 ## Security vulnerability disclosure