Docs: Don't use backtick quotes for ejabberd name

This change improves sentences legibility.
In the Introduction page, use **strong** instead.

Notice backtick quotes are for raw code in markdown, for example:
- `ejabberd` container image
- `ejabberd` script generated by OTP Release
- `ejabberd` username in system, for example for MySQL or container host

README.md

@@ -104,7 +104,7 @@ There are several places to get in touch with other ejabberd developers and admi
 License
 -------
 
-- `ejabberd` is released under the __GNU General Public License v2__ (see [COPYING](COPYING))
+- ejabberd is released under the __GNU General Public License v2__ (see [COPYING](COPYING))
 - [ejabberd translations](https://github.com/processone/ejabberd-po/) under __MIT License__.
 
 [discussions]: https://github.com/processone/ejabberd/discussions

src/ejabberd_options_doc.erl

@@ -32,7 +32,7 @@ doc() ->
         desc =>
             ?T("List of one or more "
                "_`../configuration/basic.md#host-names|host names`_ "
-               "(or domains) that 'ejabberd' will serve. This is a "
+               "(or domains) that ejabberd will serve. This is a "
                "**mandatory** option.")}},
      {listen,
       #{value => "[Options, ...]",

src/mod_register.erl

@@ -661,7 +661,7 @@ mod_doc() ->
            {access_from,
             #{value => ?T("AccessName"),
               desc =>
-                  ?T("By default, 'ejabberd' doesn't allow the client to register new accounts "
+                  ?T("By default, ejabberd doesn't allow the client to register new accounts "
                      "from s2s or existing c2s sessions. You can change it by defining "
                      "access rule in this option. Use with care: allowing registration "
                      "from s2s leads to uncontrolled massive accounts creation by rogue users.")}},