Convert Specification to AsciiDoc from Markdown

[msgilligan]

In our weekly meetings, we've agreed that we want to convert the specification from markdown format to AsciiDoc(tor) format.

I've created a DRAFT pull request PR #329 to do this, but I wanted to have a little discussion about how best to merge the changes. I've also created PR #332 to convert the other documents in this repo.

The Omni Documentation repo is already in AsciiDoc format and Getting Started with Omni Development now includes a Working with Asciidoctor format section.

My proposal is that we do the following:

1. Merge PR Convert the spec to AsciiDoc format #335
2. Rebase the two outstanding PRs with Github-markdown formatted changes (PR Added Send All #313 and PR initial updates for OmniDex 2.0 #316) to the updated master branch.
3. Add additional commits to PR Added Send All #313 and PR initial updates for OmniDex 2.0 #316 that convert the changes in the PR to AsciiDoc format.
4. Merge PR Asciidoctor Github Action #329 To enable Github Actions to generate PDF and downloadable HTML versions of the Spec.

If consensus forms around this approach, I'll make it happen.

@CraigSellars @achamely @marvgmail @dexX7

[achamely]

#332 looks good to me and i'm on board with this approach

[msgilligan]

OK, PR #335 is merged.
PR #329 is ready for review/merge.
And I've submitted a PR to @marvgmail to update is OmniDex 2 PR to AsciiDoc format.

[msgilligan]

The conversion is complete. Additional work remains to get PR #313 and PR #316 merged, but we don't need this issue open to track that.