docs: GEMINI.md updates (#729)

- Rename to `GEMINI.md` (in capital).
- Refine instructions.

Author: ishymko

Gemini.md GEMINI.mdGemini.md renamed to GEMINI.md

@@ -3,25 +3,18 @@
 ## Project frameworks
 - uv as package manager
 
-## How to run all tests
-1. If dependencies are not installed, install them using the following command
-   ```
-   uv sync --all-extras 
-   ```
-
-2. Run tests
-  ```
-  uv run pytest
-  ```
-
-## Other instructions
+## Code style and mandatory checks
 1. Whenever writing python code, write types as well.
 2. After making the changes run ruff to check and fix the formatting issues
    ```
    uv run ruff check --fix
+   uv run ruff format
    ```
 3. Run mypy type checkers to check for type errors
    ```
    uv run mypy
    ```
 4. Run the unit tests to make sure that none of the unit tests are broken.
+  ```
+  uv run pytest
+  ```