fix(redis-haproxy): add warning about HAProxy connection limit

[sc-zenokerr]

Fixes #3391

Question: I am not sure this is the right part of the document to add this. Where do you think is best?

[Frzk]

Question: I am not sure this is the right part of the document to add this. Where do you think is best?

To me, the whole "Scalingo for Caching" section should be reworked following the same structure as the one used for PG, MySQL or OpenSearch.
You'd then have a "Limitations" page where it would belong.

... But that would mean reworking the whole section, which is probably not a priority right now.

For now, I would add a h2 "Limitations" title at the bottom of the page and list it here.

[sc-zenokerr]

Good call — I added a ## Limitations section at the bottom of the page and moved the HAProxy connection limit warning there to match the other database docs.

[Frzk]

A few nitpicks and it's OK for me :)
Thanks a lot <3

[Frzk]

I'd remove the warning block:

Suggested change

	{% warning %}
	When using a Business plan, the HAProxy instances serving as entry points to your cluster have a default limit of **2,000 concurrent TCP connections**.
	If this limit is reached, any new connection will be abruptly refused.
	This can result in "Connection timed out" errors such as:
	- _Redis::CannotConnectError : Connection timed out_
	{% endwarning %}
	When using a Business plan, the HAProxy instances serving as entry points to your cluster have a default limit of **2,000 concurrent TCP connections**.
	If this limit is reached, any new connection will be abruptly refused. This can result in errors such as:
	```shell
	Redis::CannotConnectError : Connection timed out

[sc-zenokerr]

Making that change results in the notice being mixed with the redis trademark notice:

I could add a trademark notice heading (which appears in the menu and search etc) like this:

Or something else. WDYT?

[sc-zenokerr]

BTW. I haven't pushed any changes... I'm looking for your opinion first!

[Frzk]

@benjaminach: I'm wondering if the notice is still mandatory... Any thoughts about it?