fix: document CBOR in /reframe?q=

[lidel]

Due to miscommunication, go-delegated-routing v0.6.0 uses DAG-CBOR in ?q (and not DAG-JSON, like we expected) 🙈
Details: ipld/edelweiss#61

This PR updates the spec to describe the current pre-alpha implementation that shipped with Kubo 0.16

TODO: make decision if we change spec, or fix implementation

👉 If we are not planning to surgically fix this SOON (as proposed in ipld/edelweiss#61) I suggest we update specs to reflect implementation

[willscott]

this does appear to reflect reality

maybe worth a comment about spaces being url encoded to '+'s and not being percent encoded? (although it's probably safer to percent encode them first and the decoder will take that as well)

[lidel]

This turned out to be a big time sink – existing wire format and implementation has other issues, such as buffering streaming responses due to Etag generation.

I am closing this – if we want to fix Reframe we should stop bending backward and changing specs to fix broken implementation – only way forward for Reframe over HTTP is to implement #327