improve the installation docker guide for beginners (#600)

Author: unixfox

docs/installation.md

@@ -26,6 +26,8 @@ Ensure [Docker Engine](https://docs.docker.com/engine/install) and [Docker Compo
 
 Note: Currently the repository has to be cloned, this is because the `init-invidious-db.sh` file and the `config/sql` directory have to be mounted to the postgres container (See the volumes section in the docker-compose file below). This "problem" will be solved in the future.
 
+Make sure to run the newer Docker Compose V2: https://docs.docker.com/compose/install/linux/. It should already be installed if you can successfully run the command `docker compose` (with a space between the two words).
+
 ??? warning "About po_token and visitor_data identities"
 
     po_token known as Proof of Origin Token. This is an attestation token generated by a complex anti robot verification system created by Google named BotGuard/DroidGuard. It is used to confirm that the request is coming from a genuine device.
@@ -45,13 +47,13 @@ Note: Currently the repository has to be cloned, this is because the `init-invid
     You will need to copy these two parameters in the third step.  
     Subsequent usage of this same token will work on the same IP range or even the same ASN. The point is to generate this token on a blocked IP as "unblocked" IP addresses seems to not generate a token valid for passing the checks on a blocked IP.  
 
-3.  Execute these commands:
+2.  Execute these commands:
     ```bash
     git clone https://github.com/iv-org/invidious.git
     cd invidious
     ```
 
-4.  Edit the docker-compose.yml with this content:
+3.  Edit the docker-compose.yml with this content:
 
     ```docker
     version: "3"
@@ -128,6 +130,12 @@ Note: Currently the repository has to be cloned, this is because the `init-invid
 
     Note: This compose is made for a true "production" setup, where Invidious is behind a reverse proxy. If you prefer to directly access Invidious, replace `127.0.0.1:3000:3000` with `3000:3000` under the `ports:` section.
 
+4. Run the docker composition:
+
+```
+docker compose up -d
+```
+
 
 ### Docker-compose method (development)