add tests to isin, rename to polars_istr

.gitignore

@@ -89,4 +89,5 @@ docs/_build/
 
 # Polars Extension
 .so
-.dll
+.dll
+

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 repos:
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.2.1
+  rev: v0.2.2
   hooks:
     # Run the linter.
     - id: ruff

CONTRIBUTING.md

@@ -10,4 +10,26 @@ For all feature related work, it would be great to ask yourself the following qu
 
 ## Remember to run these before committing:
 1. pre-commit. We use ruff.
-2. cargo fmt
+2. cargo fmt
+
+## How to get started?
+
+Take a look at the Makefile. Set up your environment first. Then take a look at the tutorial here, and grasp the basics of maturin here.
+
+Then find a issue/feature that you want to improve/implement!
+
+## A word on Doc, Typo related PRs
+
+For docs and typo fix PRs, we welcome changes that:
+
+1. Fix actual typos and please do not open a PR for each typo.
+
+2. Add explanations, docstrings for previously undocumented features/code.
+
+3. Improve clarification for terms, explanations, docs, or docstrings.
+
+4. Fix actual broken UI/style components in doc/readme.
+
+Simple stylistic change/reformatting that doesn't register any significant change in looks, or doesn't fix any previously noted problems will not be approved.
+
+Please understand, and thank you for your time.