Link to guidance for creating a release

[duncandewhurst]

I'm creating a separate issue for this task from #54 (comment):

* [ ]  Review the guidance for creating a release and decide where it will be linked from

Currently, the instructions for creating a release are linked from two places: Release withheld information and the mapping for BT-701-notice (notice identifier).

I think it would be helpful to add a sub-heading to how to use this profile before 'post-processing steps' with a link to the instructions for creating a release so that implementers know to do that before mapping other fields. The heading could be either 'Convert a notice to OCDS format' or 'Publish a notice in OCDS format', e.g.

Convert a notice to OCDS format

Create a release and map each field on the notice according to the field mappings.

@jpmckinney does that sound good?

[jpmckinney]

Yes, sounds good!

[duncandewhurst]

Done in bd2f108