Update logo, docs styling, and changelog for 0.5.3

- Update logo
- Set logo background color to #0c0f41
- Add changelog entry for version 0.5.3

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: araufuturice

docs/source/_static/aito.svg

@@ -1,4 +1,13 @@
 div.sphinxsidebar {
   max-height: 100%;
   overflow-y: auto;
+}
+
+/* Logo background color */
+.wy-side-nav-search {
+  background-color: #0c0f41;
+}
+
+.wy-side-nav-search a.icon-home {
+  background-color: #0c0f41;
 }

docs/source/_static/custom.css

@@ -1,6 +1,19 @@
 Changelog
 =========
 
+0.5.3
+-----
+
+This version updates Python version support and modernizes the project infrastructure.
+
+General
+^^^^^^^
+
+- Dropped support for Python 3.6, 3.7, and 3.8 (all end-of-life). Minimum supported version is now Python 3.9.
+- Updated CI/CD to test only on Python 3.11.
+- Migrated documentation hosting from ReadTheDocs to GitHub Pages.
+- Added ``./do deploy-docs`` command for manual documentation deployment.
+
 0.5.2
 -----