Update docs
Update docs

- Use "resource" terminology instead of "item"
- s/ResourceHttpOptions/CollectionHttpOptions/ and
  s/ItemHttpOptions/ResourceHttpOptions/

nobesnickr/zf-hal,weierophinney/zf-api-problem,Cube-Solutions/zf-hal,vixriihi/zf-jsonld,nocvp/zf-api-problem,weierophinney/zf-api-problem,rstgroup/zf-api-problem,rstgroup/zf-api-problem,Wilt/zf-rest,Cube-Solutions/zf-hal,weierophinney/zf-api-problem,rstgroup/zf-api-problem,Wilt/zf-hal,Cube-Solutions/zf-hal,nocvp/zf-rest