Update the documentation for issue-31

Set the default nodejs version to 12 as per https://github.com/perara/wg-manager/issues/31
Also set the pip install to pip3 as we are using python3.

This was causing some issues with the wheel setup
  error: invalid command 'bdist_wheel'
  ----------------------------------------
  ERROR: Failed building wheel for python-multipart
  ERROR: Failed building wheel for sqlalchemy-utils
  ERROR: Failed building wheel for Tempita

Also set these as being used by sudo otherwise the venv has an issue with the permissions

ERROR: Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/opt/wg-manager/wg_dashboard_backend/venv/lib/python3.8/site-packages/typing_extensions.py'
Consider using the `--user` option or check the permissions.

Attempting to use the --user flag does not work

This works (once the requirements.txt file has been edited to set the sqlalchemy version to < 1.4.0 due to a versioning issues with API calls)
ImportError: cannot import name '_ColumnEntity' from 'sqlalchemy.orm.query' (/opt/wg-manager/wg_dashboard_backend/venv/lib/python3.8/site-packages/sqlalchemy/orm/query.py)
https://stackoverflow.com/questions/66644975/importerror-cannot-import-name-columnentity-from-sqlalchemy-orm-query


Working as below
INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)

docs/install.md

@@ -35,7 +35,7 @@ sudo apt-get install -y nodejs
 ### Node.JS: Debian
 ```
 sudo apt install curl
-curl -sL https://deb.nodesource.com/setup_13.x | sudo bash -
+curl -sL https://deb.nodesource.com/setup_12.x | sudo bash -
 sudo apt-get install -y nodejs
 ```
 ### WireGuard: Ubuntu
@@ -78,7 +78,7 @@ sudo apt install wireguard wireguard-tools -y
 # Building frontend
 sudo git clone https://github.com/perara/wg-manager.git /opt/wg-manager
 cd /opt/wg-manager/wg_dashboard_frontend
-sudo npm install > /dev/null && sudo npm install @angular/cli > /dev/null
+sudo npm install --unsafe-perm > /dev/null && sudo npm install @angular/cli > /dev/null
 sudo node_modules/@angular/cli/bin/ng build --configuration="production"
 ```
 One thing to be aware of is that when issuing the `sudo node_modules/@angular/cli/bin/ng build --configuration="production"` command, if you do not have enough memory on your server, the process will get "Killed". This happens when trying to compile on the lowest tier DIgital Ocean droplet. To get around this you can either add more memory or create a swap file. Here is a great guide on [creating a swap file](https://linuxize.com/post/create-a-linux-swap-file/).
@@ -88,9 +88,9 @@ One thing to be aware of is that when issuing the `sudo node_modules/@angular/cl
 sudo mv dist ../wg_dashboard_backend/build
 cd ../wg_dashboard_backend/
 sudo python3 -m venv venv && source venv/bin/activate
-pip install -r requirements.txt
+sudo pip3 install -r requirements.txt
-pip install uvicorn
+sudo pip3 install uvicorn
-uvicorn main:app --host=0.0.0.0
+sudo uvicorn main:app --host=0.0.0.0
 ```
 
 ## 5. Complete