OME005: navigation, state-of-art and resolution cleanup

[sbesson]

Primarily motivated by the discussion of https://forum.image.sc/t/software-for-whole-slide-image-wsi-analysis-with-api-to-add-deep-learning-models/28748 as well as various feedback, this PR tidies up the official proposal used for the pyramidal OME-TIFF extension by:

• restricting the title and the scope of the proposal to the OME-TIFF format
• improving the navigation by fixing headings, adding anchors and a table of content
• including a paragraph in the introduction with an explicit acknowledgement of all the TIFF-based pyramidal formats examined during the initial scoping phase and which served as inspirations for the proposal
• moving the sample files under the Format section
• adding a Resolution sub-section to each of the sections linking to the decisions and/or documentation/software releases

[sbesson]

All the relevant internal and external parties have been pointed to these changes. So far no objection has been raised either publicly or privately. I will leave a few more days for comments and then merge this PR in order to resolve the claims made on the image.sc.