Adjust logo sizing: reduce README icon to 150px and add sidebar CSS

- Reduce README logo width from 200px to 150px for better proportion
- Add custom CSS to limit Sphinx sidebar logo to 60% width

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: laughingman7743

README.md

@@ -2,7 +2,7 @@
 
 <div align="center">
 
-<img src="docs/_static/icon.png" alt="PyAthena logo" width="200">
+<img src="docs/_static/icon.png" alt="PyAthena logo" width="150">
 
 | | |
 | --- | --- |

docs/_static/custom.css

@@ -4,6 +4,12 @@ table.docutils td {
     text-align: left !important;
 }
 
+/* Limit sidebar logo size */
+img.sidebar-logo {
+    max-width: 60% !important;
+    margin: 0 auto !important;
+}
+
 /* Align table itself to the left */
 table.docutils {
     margin-left: 0;