Change the notation in the Glossary from `; TERM` to `{ TERM }`

[geo2a]

Currently, the Consensus Glossary uses the ; TERM notation in every definition. This allows to search for TERM more easily with CTRL-F in a browser.

The Genesis docs (see the PR, soon to be merged) use the { TERM } notation, which seems like a better fit for longer term names.

If time permits, we should switch the glossary from the ; notation to the new {} notation.