Add comprehensive documentation for LeagueLedger

- Created architecture overview in development/architecture.md
- Added installation guide in getting-started/installation.md
- Developed user guide with detailed instructions in user-guide/overview.md, user-guide/teams.md, user-guide/qr-codes.md
- Implemented social login setup documentation in social_login_setup.md
- Updated index.md to include links to new documentation sections
- Configured mkdocs.yml for site structure and theme
- Added requirements.txt for documentation dependencies

.readthedocs.yaml

@@ -0,0 +1,22 @@
+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the OS, Python version and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+
+# Build documentation in the docs/ directory with MkDocs
+mkdocs:
+  configuration: mkdocs.yml
+  fail_on_warning: false
+
+# Optionally declare the Python requirements required to build your docs
+python:
+  install:
+    - requirements: docs/requirements.txt