Revert "refact: drop requirements.txt"

This reverts commit eca4978.
The file requirements.txt is used for mkdocs, not for building the project.

Author: boriel

requirements.txt

@@ -0,0 +1,29 @@
+babel==2.16.0
+certifi==2024.8.30
+charset-normalizer==3.4.0
+click==8.1.7
+colorama==0.4.6
+ghp-import==2.1.0
+idna==3.10
+Jinja2==3.1.4
+Markdown==3.7
+MarkupSafe==3.0.2
+mergedeep==1.3.4
+mkdocs==1.6.1
+mkdocs-get-deps==0.2.0
+mkdocs-material==9.5.44
+mkdocs-material-extensions==1.3.1
+packaging==24.2
+paginate==0.5.7
+pathspec==0.12.1
+platformdirs==4.3.6
+Pygments==2.18.0
+pymdown-extensions==10.12
+python-dateutil==2.9.0.post0
+PyYAML==6.0.2
+pyyaml_env_tag==0.1
+regex==2024.11.6
+requests==2.32.3
+six==1.16.0
+urllib3==2.2.3
+watchdog==6.0.0