SBVR12 — SBVR issue: Misc. styling & caption fixes

Some entries of SBVR 1.2 have styling and captioning errors that need to be fixed

1) the entry "unitary verb concept" has a styling error in the 1st Necessity.
Here is how the entry appears in SBVR 1.2:

The term "unitary verb concept" should be in term styling.
2) the entry "proposition is possibly true" is missing a caption.
Here is how the entry appears in SBVR 1.2:

The second line of text needs a "Possibility:" caption, the first word of the sentence needs to be capitalized, and the wording needs to be clarrified.
3) The entry "proposition is obligated to be false" has a styling error in its Definition text.
Here is how the entry appears in SBVR 1.2:

The word "not" should be in keyword styling.
4) The entry "concept has implied characteristic" has a styling error in its Definition text.
Here is how the entry appears in SBVR 1.2:

The word "does" should be in verb styling.
5) the entry "categorization scheme contains category" is missing a caption.
Here is how the entry appears in SBVR 1.2:

The line following the Synonymous Form caption — i.e., with the value "partitive verb concept" — needs a "Concept Type:" caption.