docs: allow long table reference links to wrap and prevent overflow

Some documentation pages contain docutils tables with reference links
that use long unbroken strings. Those strings can expand the table
width beyond the content column and cause page-wide horizontal
overflow.

Allow reference links in docutils tables in the main document body to
wrap when needed so the table stays within the content column and does
not break page layout.

Examples:
  https://docs.kernel.org/6.15/arch/openrisc/openrisc_port.html
  https://docs.kernel.org/6.15/filesystems/ext2.html

Signed-off-by: Rito Rhymes <rito@ritovision.com>
Assisted-by: Codex:GPT-5.4
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260323152428.30483-2-rito@ritovision.com>

Documentation/sphinx-static/custom.css

@@ -165,6 +165,11 @@ code.docutils.literal span.pre {
     overflow-wrap: anywhere;
 }
 
+/* Let rendered reference links in tables wrap when needed. */
+div.body table.docutils a.reference {
+    overflow-wrap: anywhere;
+}
+
 /* Make xrefs more universally visible */
 a.reference, a.reference:hover {
     border-bottom: none;