docs(contributing): add poetry and lychee tips

Author: bearomorphism

docs/contributing_tldr.md

@@ -12,6 +12,9 @@ Please check the [pyproject.toml](https://github.com/commitizen-tools/commitizen
 ### Code Changes
 
 ```bash
+# Make sure you have the latest version of poetry installed
+poetry self update
+
 # Ensure you have the correct dependencies, for nix user's see below
 poetry install
 
@@ -36,6 +39,13 @@ pytest -n auto <test_suite>
 poetry doc
 ```
 
+Also, we use [Lychee](https://lychee.cli.rs/) to check for broken links in the documentation.
+
+```bash
+# Check for broken links in the documentation
+lychee .
+```
+
 ### Nix Users
 
 If you are using Nix, you can install poetry locally by running: