Adding Upgrade docs

README.md

 ```
 
 Select the option `Y` (yes) and it'll be done
+
+## Upgrading
+
+See the [upgrade docs](./docs/upgrading/README.md)

docs/upgrading/README.md

+# Upgrade docs
+
+## Moving from v1.105 to v1.126
+
+To migrate from v1.105 to v1.126 you need to follow these steps:
+
+1. Copy the latest content of the [docker-compose.yaml](../../docker-compose.yaml) file, all of it and override the file `/opt/matrix/docker-compose.yaml` in the server with the latest content.
+2. Modify the nginx config by removing the following lines from the `/etc/nginx/sites-enabled/default` config file (remove all of them):
+
+```
+    location ~ ^/(client/|_matrix/client/unstable/org.matrix.msc3575/sync) {
+        proxy_pass http://10.10.10.7:8008;
+        proxy_set_header X-Forwarded-For \$remote_addr;
+        proxy_set_header X-Forwarded-Proto \$scheme;
+        proxy_set_header Host \$host;
+    }
+```
+
+3. Edit the same file and look for the word `org.matrix.msc3575.proxy`. Change it for `m.identity_server`
+4. Add the following value to the file `/opt/matrix/config/synapse/homeserver.yaml` (Change the `DOMAIN` value accordingly!!):
+
+```yaml
+public_baseurl: "https://DOMAIN"
+```
+
+5. Now it's time to bunce it all, run the following as root:
+
+```
+# Restart nginx
+% nginx -s reload
+# Restart matrix
+% systemctl restart matrix.service
+```
+
+6. Give it a few minutes to come back up and you are ready to go :)

install.sh

         proxy_http_version 1.1;
     }
 
-    # Proxy for Synapse Admin Panel
-    location /_synapse/admin {
-        proxy_pass http://10.10.10.4:8008;
-        proxy_set_header X-Forwarded-For \$remote_addr;
-        proxy_set_header X-Forwarded-Proto \$scheme;
-        proxy_set_header Host \$host;
-        client_max_body_size 50M;
-        proxy_http_version 1.1;
-    }
-
     # Sydent identity server
     location ~ ^(/_matrix/identity) {
         proxy_pass http://10.10.10.5:8090;