Added information on updating the stable version of TDE to README.md

Signed-off-by: ormorph <roma251078@mail.ru>

README.md

@@ -104,3 +104,28 @@ before your ``` emerge ``` command.
 Where the ``` * ``` at the end stands for the component you are going to emerge from, like ``` TDELIBS ``` and the branch you can get from some PR, you may want to test, can be added by:
 
 ``` EGIT_OVERRIDE_BRANCH_GITEA_TDE_TDELIBS="fix/crash" ```, for example.
+
+-----
+
+### Updating the stable version of TDE
+
+Layman has now been removed from the main Gentoo branch, so it is recommended to configure the overlay via the `/etc/portage/repos.conf/tde.conf` file. See example above.
+
+Overlay update:
+```
+# emaint sync  -r trinity-official
+```
+
+First you need to unmask the stable version:
+```
+# cd /var/db/repos/trinity-official
+# Documentation/scripts/create_list_keywords.sh 14.1.1 >/etc/portage/package.accept_keywords/tde
+```
+where `14.1.1` is the TDE version you need to update.
+Next you need to update TDE. Since `trinity-base/tdelibs` can use header files from a previously installed version of `trinity-base/tdelibs` when building, this package must be removed before building.
+
+TDE update:
+```
+# emerge -C trinity-base/tdelibs
+# emerge -avuNDU @world
+```