Separates the installation of pre-commit to -f|--format case in orbit.sh (#28)

* Separate install of `pre-commit` to `-f|--format` case
* Always execute `pre-commit` inside the Orbit directory
* Instruct contributors to run `pre-commit` with `./orbit.sh --format`

---------
Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -40,7 +40,7 @@ To upload images to a PR -- simply drag and drop an image while in edit mode and
 
 ## Checklist
 
-- [ ] I have run the [`pre-commit` checks](https://pre-commit.com/) with `pre-commit run --all-files` (see [here](https://pre-commit.com/#install) instructions to set it up)
+- [ ] I have run the [`pre-commit` checks](https://pre-commit.com/) with `./orbit.sh --format`
 - [ ] I have made corresponding changes to the documentation
 - [ ] My changes generate no new warnings
 - [ ] I have added tests that prove my fix is effective or that my feature works

docs/source/refs/contributing.rst

@@ -76,7 +76,7 @@ following command in the terminal:
 
 .. code:: bash
 
-   pre-commit run --all-files
+   ./orbit.sh --format
 
 Maintaining a changelog
 -----------------------

docs/source/setup/developer.rst

@@ -248,4 +248,4 @@ To run over the entire repository, please execute the following command in the t
 
 .. code:: bash
 
-   pre-commit run --all-files
+   ./orbit.sh --format

orbit.sh

@@ -110,8 +110,6 @@ while [[ $# -gt 0 ]]; do
             # this does not check dependencies between extensions
             export -f extract_isaacsim_python
             export -f install_orbit_extension
-            # initialize git hooks
-            pip install pre-commit
             # source directory
             find -L "${ORBIT_PATH}/source/extensions" -mindepth 1 -maxdepth 1 -type d -exec bash -c 'install_orbit_extension "{}"' \;
             # unset local variables
@@ -146,8 +144,15 @@ while [[ $# -gt 0 ]]; do
             ;;
         # run the formatter over the repository
         -f|--format)
+            if ! command -v pre-commit &>/dev/null; then
+                echo "[INFO] Installing pre-commit..."
+                pip install pre-commit
+            fi
             echo "[INFO] Formatting the repository..."
+            # always execute inside the Orbit directory
+            cd "${ORBIT_PATH}"
             pre-commit run --all-files
+            cd -
             shift # past argument
             # exit neatly
             break