Add CI pipelines and pre-commit hooks

Now we have a very basic CI pipeline for running tests and executing
linter, as well as a pre-commit hook that is checking basic code related
stuff. The pre-commit hook is executed as a part of pipelines as well

Signed-off-by: Nikolai Rodionov <allanger@badhouseplants.net>

.woodpecker/code_tests.yaml

@@ -0,0 +1,13 @@
+when:
+  event:
+    - push
+steps:
+  - name: Clippy linter
+    image: rust:1.91.1-bullseye
+    commands:
+      - rustup component add clippy
+      - cargo clippy
+  - name: Unit tests
+    image: rust:1.91.1-bullseye
+    commands:
+      - cargo test