[conf] Use sphinx_tippy

Author: SilverRainZ

_static/tippy-custom.css

@@ -0,0 +1,7 @@
+/* https://sphinx-tippy.readthedocs.io/en/latest/ */
+
+.tippy-box {
+    background-color:var(--pst-color-surface);
+    color:var(--pst-color-text-base);
+    border: 1px solid var(--pst-color-border);
+}

conf.py

@@ -544,3 +544,9 @@ def url(self) -> str:
 if D is Deployment.Local:
     # Speed up local incremental HTML build (may cause document inconsistencies).
     extensions.append('sphinxnotes.fasthtml')
+
+extensions.append('sphinx_tippy')
+tippy_rtd_urls = [
+    'https://www.sphinx-doc.org/en/master/',
+]
+html_css_files.append('tippy-custom.css')