Docs: Refactor CONTRIBUTING.md for clarity and linting compliance

.github/CONTRIBUTING.md

@@ -1,53 +1,52 @@
 # Contributing to KivyMD
 
-### I need a support
+## I need support
 
-* **Do not create an issue.** You can find support information in
-[README](https://github.com/kivymd/KivyMD#support).
+- **Please do not create an issue.** You can find support information in
+  [README](https://github.com/kivymd/KivyMD#support).
 
-### I found a bug
+## I found a bug
 
-* **Check that this bug isn't already reported:**
-[issues on GitHub](https://github.com/kivymd/KivyMD/issues).
-* Create new issue with
-[Bug report template](https://github.com/kivymd/KivyMD/issues/new?template=bug_report.md).
-* Write good **title** and clear **description**, paste **code sample** and, if
-possible, attach a **screenshot**.
+- **Verify that this bug hasn't already been reported:**
+  [issues on GitHub](https://github.com/kivymd/KivyMD/issues).
+- Create a new issue with
+  [Bug report template](https://github.com/kivymd/KivyMD/issues/new?template=bug_report.md).
+- Provide a descriptive **title**, add a clear **description**, include a
+  **code sample** and, if possible, attach a **screenshot**.
 
-### I want to suggest a new feature
+## I want to suggest a new feature
 
-* **Check that similar feature isn't already published:**
-[issues on GitHub](https://github.com/kivymd/KivyMD/issues).
-* Create new issue with
-[Feature request template](https://github.com/kivymd/KivyMD/issues/new?template=feature_request.md).
-* Write good **title** and clear **description**, paste **code sample** and, if
-possible, attach an **images**.
+- **Check if a similar feature has already been published:**
+  [issues on GitHub](https://github.com/kivymd/KivyMD/issues).
+- Create a new issue with
+  [Feature request template](https://github.com/kivymd/KivyMD/issues/new?template=feature_request.md).
+- Provide a descriptive **title**, add a clear **description**, include a
+  **code sample** and, if possible, attach **images**.
 
-### I have a changes
-
-* **Check that similar changes isn't already requested:**
-[pull requests on GitHub](https://github.com/kivymd/KivyMD/pulls).
-* Format your code with [Black](https://github.com/psf/black) utility. Use
-[pre-commit](https://pre-commit.com/) to automatically format code before
-commit.
-* Do not forget to test your code.
-* Create new [pull request](https://github.com/kivymd/KivyMD/compare).
-* Write good **title** and **description of changes** and, if possible, attach
-a **screenshots**.
+## I have changes
 
+- **Check if similar changes have already been requested:**
+  [pull requests on GitHub](https://github.com/kivymd/KivyMD/pulls).
+- Format your code with the [Black](https://github.com/psf/black) utility. Use
+  [pre-commit](https://pre-commit.com/) to automatically format code before
+  commit.
+- Test your code locally.
+- Create a new [pull request](https://github.com/kivymd/KivyMD/compare).
+- Provide a descriptive **title** and a clear **description of the changes**
+  and, if possible, attach **screenshots**.
 
 ## What contributions can I make?
 
 See [TODO List](https://github.com/kivymd/KivyMD/issues/139)
 
-### Documentation
+## Documentation
 
 All Python code should be documented. Properties are documented in [Kivy style](https://github.com/kivy/kivy/blob/17e1977a047a21fd7c780b32572ae3948f2e7c2d/kivy/uix/button.py#L124)
 
-### Make widgets fit Material Design
+## Make widgets that adhere to Material Design
 
-All widgets should look like it drawn in Material specification: https://material.io/components/
+All widgets must adhere to the Material specifications: <https://material.io/components/>
 
-### Make widgets more customisable
+## Make widgets more customizable
 
-Widgets should have as many properties as may be required to customize it.
+Widgets should have as many properties as may be required to customize them.