Connect: Adjust layout of index page about client drivers

The previous layout was no longer able to sustain content pressure
without becoming even more confusing about the discrimination between
PostgreSQL-based drivers, and HTTP-based ones.

The new approach is to have dedicated sections for each of them. It
yields a much better guidance than before.

docs/_static/style.css

@@ -0,0 +1,12 @@
+/*
+In `crate-docs-theme`, `src/crate/theme/rtd/crate/static/css/custom.css`
+defines a style we don't want to apply here, specifically on `connect/index`.
+
+.wrapper-content-right .section img {
+  margin-bottom: 16px;
+}
+*/
+
+.wrapper-content-right .section img {
+  margin-bottom: unset !important;
+}

docs/conf.py

@@ -17,3 +17,10 @@
 ]
 
 linkcheck_timeout = 5
+
+
+html_static_path = ['_static']
+
+
+def setup(app):
+    app.add_css_file('style.css')