Fix VCL link and minor HTTP Cache related things (#3020)

* reverse_proxy.md: varnish5.vcl → varnish7.vcl+parameters.vcl
* content_aware_cache.md: Fix <sup> spacing in 1ˢᵗ and 3ʳᵈ
* reverse_proxy.md: Use latest_tag_5_0 in GitHub links

Author: adriendupuis

docs/infrastructure_and_maintenance/cache/http_cache/content_aware_cache.md

@@ -521,7 +521,7 @@ The output is:
 Now, investigate the response of each of these ESI fragments to understand what is going on.
 It's important to put that URL in single quotes as the URLS to the ESIs include special characters that can be interpreted by the shell.
 
-#### 1st ESI
+#### 1st ESI
 
 ```bash
     $ curl -IXGET --resolve www.staging.foobar.com.us-2.platformsh.site:443:1.2.3.4 --header "Surrogate-Capability: abc=ESI/1.0" --header "x-user-context-hash: daea248406c0043e62997b37292bf93a8c91434e8661484983408897acd93814" 'https://www.staging.foobar.com.us-2.platformsh.site/_fragment?_hash=B%2BLUWB2kxTCc6nc5aEEn0eEqBSFar%2Br6jNm8fvSKdWU%3D&_path=locationId%3D2%26contentId%3D52%26blockId%3D11%26versionNo%3D3%26languageCode%3Deng-GB%26serialized_siteaccess%3D%257B%2522name%2522%253A%2522site%2522%252C%2522matchingType%2522%253A%2522default%2522%252C%2522matcher%2522%253Anull%252C%2522provider%2522%253Anull%257D%26serialized_siteaccess_matcher%3Dnull%26_format%3Dhtml%26_locale%3Den_GB%26_controller%3DEzSystems%255CEzPlatformPageFieldTypeBundle%255CController%255CBlockController%253A%253ArenderAction'
@@ -549,7 +549,7 @@ Surrogate-Key: ez-all c52 l2
 The headers here look correct and don't indicate that this ESI isn't cached by the HTTP cache.
 The second ESI has a similar response.
 
-#### 3rd ESI
+#### 3rd ESI
 
 ```bash
     $ curl -IXGET --resolve www.staging.foobar.com.us-2.platformsh.site:443:1.2.3.4 --header "Surrogate-Capability: abc=ESI/1.0" --header "x-user-context-hash: daea248406c0043e62997b37292bf93a8c91434e8661484983408897acd93814" 'https://www.staging.foobar.com.us-2.platformsh.site//_fragment?_hash=lnKTnmv6bb1XpaMPWRjV3sNazbn9rDXskhjGae1BDw8%3D&_path=locationId%3D2%26contentId%3D52%26blockId%3D13%26versionNo%3D3%26languageCode%3Deng-GB%26serialized_siteaccess%3D%257B%2522name%2522%253A%2522site%2522%252C%2522matchingType%2522%253A%2522default%2522%252C%2522matcher%2522%253Anull%252C%2522provider%2522%253Anull%257D%26serialized_siteaccess_matcher%3Dnull%26_format%3Dhtml%26_locale%3Den_GB%26_controller%3DEzSystems%255CCustomBundle%255CController%255CFooController%253A%253AcustomAction'

docs/infrastructure_and_maintenance/cache/http_cache/reverse_proxy.md

@@ -47,8 +47,11 @@ Using a different proxy is highly recommended as they provide better performance
 
 For reverse proxies to work properly with your installation, you need to add the corresponding VCL files for your HTTP Cache.
 
-- [Varnish VCL xkey example](https://github.com/ibexa/http-cache/blob/main/docs/varnish/vcl/varnish5.vcl)
-- Fastly can be found in `vendor/ibexa/fastly/fastly`. You must install the following to use Fastly:
+- Varnish config can be found in `vendor/ibexa/http-cache/docs/varnish/vcl`:
+    - use [parameters.vcl](https://github.com/ibexa/http-cache/blob/v[[= latest_tag_5_0 =]]/docs/varnish/vcl/parameters.vcl) for installation specific settings
+    - plus one of the `varnish*.vcl` corresponding to your Varnish version
+        - For example, [varnish7.vcl](https://github.com/ibexa/http-cache/blob/v[[= latest_tag_5_0 =]]/docs/varnish/vcl/varnish7.vcl) when using Varnish 7
+- Fastly config can be found in `vendor/ibexa/fastly/fastly`. You must install the following to use Fastly:
     - `ibexa_main.vcl` as the **main** custom VCL
     - `ibexa_user_hash.vcl` as another custom VCL
     - `snippet_re_enable_shielding.vcl` as snippet