Add pre-commit config and update README

See also https://src.fedoraproject.org/tests/llvm/pull-request/27

.pre-commit-config.yaml

@@ -0,0 +1,14 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+- repo: https://github.com/pre-commit/pre-commit-hooks
+  rev: v4.5.0
+  hooks:
+  -   id: trailing-whitespace
+  -   id: end-of-file-fixer
+
+# See https://tmt.readthedocs.io/en/latest/guide.html#checking-data-validity
+- repo: https://github.com/teemtee/tmt.git
+  rev: 1.32.2
+  hooks:
+  - id: tmt-lint

README.md

@@ -105,3 +105,19 @@ tier: 1
 # tag+:
 #   - sometag
 ```
+
+### Avoid common errors using pre-commit
+
+This project uses [`pre-commit`](https://pre-commit.com/)
+
+* to [lint fmf files](https://tmt.readthedocs.io/en/latest/guide.html#lint)
+* to check that you don't have [trailing
+  whitespaces](https://github.com/pre-commit/pre-commit-hooks?tab=readme-ov-file#trailing-whitespace)
+* to check that [files end with a
+  newline](https://github.com/pre-commit/pre-commit-hooks?tab=readme-ov-file#end-of-file-fixer)
+
+Please install `pre-commit` using `pip install pre-commit` as described
+[here](https://pre-commit.com/#install). Then navigate to your clone of this
+project and install the git hook scripts using `pre-commit install`. This will
+run pre-commit on every `git commit` that you make in this repository from now
+on.