qdoc manual: explain how to get \c{*/} working in the documentation

It turns out that text containing '*/' will actually close the qdoc comment and break everything that came afterwards.

For example,

\c{**/.qmlls.ini}

will break the documentation but

\tt{**\/.qmlls.ini}

is fine.

Now, there should be a page like https://doc.qt.io/qt-6/04-qdoc-commands-textmarkup.html#double-backslash that explains that you can also escape forward slashes, and a note in https://doc.qt.io/qt-6/04-qdoc-commands-textmarkup.html#c-code-font and https://doc.qt.io/qt-6/04-qdoc-commands-textmarkup.html#tt-command that (inline) code containing a '*/' needs to use \tt instead of \c and to escape the forward slash to avoid closing the qDoc comment.

Something similar should be also done for the \code, \badcode, \qml and similar environments on how to handle '*/' in code snippets., but I am not sure what workaround is required there.