nixos: fix backticks in Markdown descriptions

nixos/modules/config/mysql.nix

···
                 example = "pid";
                 description = lib.mdDoc ''
                   The name of the column in the log table to which the pid of the
-                  process utilising the `pam_mysql's` authentication
+                  process utilising the `pam_mysql` authentication
                   service is stored.
                 '';
               };

nixos/modules/security/acme/default.nix

···
           Default values inheritable by all configured certs. You can
           use this to define options shared by all your certs. These defaults
           can also be ignored on a per-cert basis using the
-          `security.acme.certs.''${cert}.inheritDefaults' option.
+          {option}`security.acme.certs.''${cert}.inheritDefaults` option.
         '';
       };
 

nixos/modules/security/audit.nix

···
         type        = types.enum [ false true "lock" ];
         default     = false;
         description = lib.mdDoc ''
-          Whether to enable the Linux audit system. The special `lock' value can be used to
+          Whether to enable the Linux audit system. The special `lock` value can be used to
           enable auditing and prevent disabling it until a restart. Be careful about locking
           this, as it will prevent you from changing your audit configuration until you
           restart. If possible, test your configuration using build-vm beforehand.

nixos/modules/services/audio/mpd.nix

···
           Extra directives added to to the end of MPD's configuration file,
           mpd.conf. Basic configuration like file location and uid/gid
           is added automatically to the beginning of the file. For available
-          options see `man 5 mpd.conf`'.
+          options see {manpage}`mpd.conf(5)`.
         '';
       };
 

nixos/modules/services/misc/gpsd.nix

···
         type = types.bool;
         default = false;
         description = lib.mdDoc ''
-          Whether to enable `gpsd', a GPS service daemon.
+          Whether to enable `gpsd`, a GPS service daemon.
         '';
       };
 

nixos/modules/services/misc/weechat.nix

···
       default = "/var/lib/weechat";
     };
     sessionName = mkOption {
-      description = lib.mdDoc "Name of the `screen' session for weechat.";
+      description = lib.mdDoc "Name of the `screen` session for weechat.";
       default = "weechat-screen";
       type = types.str;
     };

nixos/modules/services/networking/avahi-daemon.nix

···
         Whether to run the Avahi daemon, which allows Avahi clients
         to use Avahi's service discovery facilities and also allows
         the local machine to advertise its presence and services
-        (through the mDNS responder implemented by `avahi-daemon').
+        (through the mDNS responder implemented by `avahi-daemon`).
       '';
     };
 
···
       default = false;
       description = lib.mdDoc ''
         Whether to enable the mDNS NSS (Name Service Switch) plug-in.
-        Enabling it allows applications to resolve names in the `.local'
+        Enabling it allows applications to resolve names in the `.local`
         domain by transparently querying the Avahi daemon.
       '';
     };

nixos/modules/services/networking/gnunet.nix

···
         type = types.lines;
         default = "";
         description = lib.mdDoc ''
-          Additional options that will be copied verbatim in `gnunet.conf'.
-          See `gnunet.conf(5)' for details.
+          Additional options that will be copied verbatim in `gnunet.conf`.
+          See {manpage}`gnunet.conf(5)` for details.
         '';
       };
     };

nixos/modules/services/networking/nat.nix

···
             type = types.listOf types.str;
             default = [ ];
             example = literalExpression ''[ "55.1.2.3" ]'';
-            description = lib.mdDoc "Public IPs for NAT reflection; for connections to `loopbackip:sourcePort' from the host itself and from other hosts behind NAT";
+            description = lib.mdDoc "Public IPs for NAT reflection; for connections to `loopbackip:sourcePort` from the host itself and from other hosts behind NAT";
           };
         };
       });

nixos/modules/services/networking/rpcbind.nix

···
         type = types.bool;
         default = false;
         description = lib.mdDoc ''
-          Whether to enable `rpcbind', an ONC RPC directory service
+          Whether to enable `rpcbind`, an ONC RPC directory service
           notably used by NFS and NIS, and which can be queried
           using the rpcinfo(1) command. `rpcbind` is a replacement for
           `portmap`.

nixos/modules/services/networking/ssh/lshd.nix

···
         type = types.listOf types.str;
         description = lib.mdDoc ''
           List of network interfaces where listening for connections.
-          When providing the empty list, `[]', lshd listens on all
+          When providing the empty list, `[]`, lshd listens on all
           network interfaces.
         '';
         example = [ "localhost" "1.2.3.4:443" ];

nixos/modules/services/web-apps/hedgedoc.nix

···
                 type = types.str;
                 default = "";
                 description = lib.mdDoc ''
-                  Attribute map for `id'.
-                  Defaults to `NameID' of SAML response.
+                  Attribute map for `id`.
+                  Defaults to `NameID` of SAML response.
                 '';
               };
               username = mkOption {
                 type = types.str;
                 default = "";
                 description = lib.mdDoc ''
-                  Attribute map for `username'.
-                  Defaults to `NameID' of SAML response.
+                  Attribute map for `username`.
+                  Defaults to `NameID` of SAML response.
                 '';
               };
               email = mkOption {