fix HTML subset documentation is not very readable on smaller screens

When viewing "Supported HTML Subset" documentation in Qt Creator (in
QTextBrowser), the first table that lists all tags is quite unreadable
(see images). It happens because there is a code snippet in Comment
column for tag "meta" that uses pre-formatted text. Because it should
not be wrapped automatically, it ends up pushing first 2 columns into
their minimum size, which mostly makes them take a single letter per
row.

Task-number: QTBUG-64126
Change-Id: I08bf6f61806d52e7a2f47bdbed1b5950825ce739
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/gui/doc/src/richtext.qdoc

@@ -975,14 +975,12 @@
             \li
     \row    \li \c meta
             \li Meta-information
-            \li If a text encoding is specified using the \c{meta} tag,
-               it is picked up by Qt::codecForHtml().
-               Likewise, if an encoding is specified to
-               QTextDocument::toHtml(), the encoding is stored using
-               a \c meta tag, for example:
-
-    \snippet code/doc_src_richtext.qdoc 7
-
+            \li If a text encoding is specified using the \c{meta}
+               tag, it is picked up by Qt::codecForHtml().  Likewise,
+               if an encoding is specified to QTextDocument::toHtml(),
+               the encoding is stored using a \c meta tag, for
+               example:
+               \c {<meta http-equiv="Content-Type" content="text/html; charset=EUC-JP" />}
     \row    \li \c li
             \li List item
             \li