doc: theme & svg logo tweak, grey to slightly darker lines and font

This commits tweaks the material orange theme to use the exact color hue
of Jackys footies.  To match this and give a slightly better contrast we
also change Jacksy border and logo text color to a slightly darker tone.

The original logo.svg is retained for reference, the new logo is logo2,
which all the .png variants have now been updated to.

Signed-off-by: Joachim Wiberg <[email protected]>

Author: troglobit

doc/extra.css

@@ -0,0 +1,12 @@
+.md-header__title {
+    font-size: 1.1rem;
+    line-height: 2.6rem;
+}
+
+[data-md-color-primary="orange"] {
+    --md-primary-fg-color: #ff7f2a;
+    --md-primary-bg-color: #5c5f5c;
+}
+[data-md-color-primary="black"] {
+    --md-primary-bg-color: #5c5f5c;
+}

doc/jack.png

@@ -6,6 +6,8 @@ repo_name: kernelkit/infix
 copyright: Copyright © 2022-2025 The KernelKit Team
 docs_dir: doc/
 edit_uri: edit/master/doc/
+extra_css:
+  - extra.css
 
 exclude_docs: |
   ChangeLog.md