document all the new anchors in one page

[prjemian]

• close nxdl2rst.py: document all the new anchors in one page #879

[prjemian]

To keep this PR focused, will not work on #1057 and #1059 in this PR.

[prjemian]

@PeterC-DLS @sanbrock @woutdenolf This is ready for review. Need to checkout the branch and build locally to view the content. make local

[prjemian]

Here is where the new content is referenced:

This is a view of the HTML page (just the first part):

YAML content starts like this:

_metadata:
  datetime: '2022-06-18T19:25:37.457455'
  subtitle: Anchors for all NeXus fields, groups, attributes, and links.
  title: NeXus NXDL vocabulary.
terms:
  '@auxiliary_signals':
    /NXdata@auxiliary_signals-attribute:
      html: '#nxdata-auxiliary-signals-attribute'
      term: /NXdata@auxiliary_signals-attribute
      url: https://manual.nexusformat.org/classes/base_classes/NXdata.html#nxdata-auxiliary-signals-attribute
  '@axes':
    /NXcxi_ptycho/DATA@axes-attribute:
      html: '#nxcxi-ptycho-data-axes-attribute'
      term: /NXcxi_ptycho/DATA@axes-attribute
      url: https://manual.nexusformat.org/classes/applications/NXcxi_ptycho.html#nxcxi-ptycho-data-axes-attribute
    /NXcxi_ptycho/entry_1/instrument_1/detector_1/translation@axes-attribute:
      html: '#nxcxi-ptycho-entry-1-instrument-1-detector-1-translation-axes-attribute'
      term: /NXcxi_ptycho/entry_1/instrument_1/detector_1/translation@axes-attribute
      url: https://manual.nexusformat.org/classes/applications/NXcxi_ptycho.html#nxcxi-ptycho-entry-1-instrument-1-detector-1-translation-axes-attribute
    /NXcxi_ptycho/entry_1/instrument_1/detector_1@axes-attribute:
      html: '#nxcxi-ptycho-entry-1-instrument-1-detector-1-axes-attribute'
      term: /NXcxi_ptycho/entry_1/instrument_1/detector_1@axes-attribute
      url: https://manual.nexusformat.org/classes/applications/NXcxi_ptycho.html#nxcxi-ptycho-entry-1-instrument-1-detector-1-axes-attribute
    /NXdata/DATA@axes-attribute:
      html: '#nxdata-data-axes-attribute'
      term: /NXdata/DATA@axes-attribute
      url: https://manual.nexusformat.org/classes/base_classes/NXdata.html#nxdata-data-axes-attribute

[PeterC-DLS]

LGTM