BEP028 specifiction updates

[cmaumet]

This PR implements the following edits on the specification:

• Specify dataset-level provenance and file-level provenance using "records": 22dcefd6a64f574f9dfba3ee19591944704bf103
• Naming and location of dataset-level and file-level provenance records as discussed on March 7, 2022: https://github.com/bids-standard/BEP028_BIDSprov/pull/74/commits/075724568ead6e831dd088a8f32252b4581c71dd
• Discussions points moved at the end of the specification: e9ff2872ae9af02a902d4d1de07fab9e5c9c7148
  • A few formatting updates

[cmaumet]

This is outdated. Closing