Add documentation about why, for example, HTTP gateways are expected to support HTTP/2 and what HTTP/1.1 isn't spec compliant.

From a conversation in Filecon Slack: #filecoin-pin from @aschmahmann :

if you use http 1.1 connections browsers have a bad time. Due to the lack of multiplexing there's a very limited number of concurrent requests you can make at a time with http 1.1 (6-8 iirc) which means that supporting http 1.1 would mean users would sometimes see reasonable performance but frequently get pretty bad performance. The result is it seemed better to not support http 1.1 at all then put users in the patchwork "but it works on my small test, oh well I guess ipfs is just slow" regime.

Taking an action item on my end to get a "p2p" section added to the IPFS Gateway specs docs that covers some of the "as used in p2p environments" pieces that aren't necessarily a requirement in a non-p2p trustless gateway situation (e.g. a gateway trusted for availability but where you'd like to verify the data integrity)