Add apache2 reverse proxy documentation

[blacknell]

Closes #4496

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[blacknell]

@NickM-27 - I made the changes and I think I closed of the comment requests from your and requested a further review. I'm not convinced I did this right and that it might still be waiting on me rather than moved on to you.

[NickM-27]

@NickM-27 - I made the changes and I think I closed of the comment requests from your and requested a further review. I'm not convinced I did this right and that it might still be waiting on me rather than moved on to you.

You did it right, I've just been busy and haven't had time to review yet

[blacknell]

Can we get this merged soon 😉

[blacknell]

@NickM-27 - I committed the suggestions you made but in reviewing the deploy preview the whole section after step 1 is missing. I'm at a loss to figure out what happened.

[NickM-27]

It looks like the ``` in the docs along with the ``` of the suggestion in github caused the commit to delete the code instead of replace it like I intended. I'll create a new suggestion to fix it

[NickM-27]

Suggested change

	This Apache2 configuration snippet then results in unencrypted requests being redirected to webserver SSL port
	```xml
	<VirtualHost *:80>
	ServerName cctv.mydomain.co.uk
	RewriteEngine on
	RewriteCond %{SERVER_NAME} =cctv.mydomain.co.uk
	RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
	</VirtualHost>
	```xml
	<VirtualHost *:443>
	<Location />
	AuthType Basic
	AuthName "Restricted Files"
	AuthUserFile "/var/www/passwords"
	Require user paul
	</Location>
	</VirtualHost>
	```
	This Apache2 configuration snippet then results in unencrypted requests being redirected to webserver SSL port
	### Step 2: Use SSL to encrypt access to your Frigate instance
	Whilst this won't, on its own, stop access to your Frigate webserver it will encrypt all content (such as login credentials).
	Installing SSL is beyond the scope of this document but [Let's Encrypt](https://letsencrypt.org/) is a widely used approach.
	This Apache2 configuration snippet then results in unencrypted requests being redirected to webserver SSL port
	\`\`\`xml
	<VirtualHost *:80>
	ServerName cctv.mydomain.co.uk
	RewriteEngine on
	RewriteCond %{SERVER_NAME} =cctv.mydomain.co.uk
	RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
	</VirtualHost>
	\`\`\`
	### Step 3: Authenticate users at the proxy
	There are many ways to authenticate a website but a simple straightforward approach is to use [Apache2 password files](https://httpd.apache.org/docs/2.4/howto/auth.html).
	```xml
	<VirtualHost *:443>
	<Location />
	AuthType Basic
	AuthName "Restricted Files"
	AuthUserFile "/var/www/passwords"
	Require user paul
	</Location>
	</VirtualHost>
	\`\`\`

[NickM-27]

likely just need to copy this and remove the \ and commit on your own (not via github UI)

[blacknell]

Done (thanks). And thanks for spotting the typos for which I am rather embarrassed.