documents: try to parse the thesis note from RERO DOC more precisely

[mmo]

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[iGormilhit]

Commit message proposition:

documents: improve parsing of thesis note

* Tries to parse the thesis note from RERO DOC more precisely.

Co-Authored-by: Miguel Moreira <[email protected]>

Title: 50 chars max, infinitive verb.
Body: wrap at 72 chars, verbs at the 3rd singular person.
Always the Co-Authored-by signature, with github account e-mail.

I need to document it explicitly, I thought I did.
There's a git commit template for RERO ILS: https://github.com/rero/rero-ils/blob/dev/.gitmessage.txt (see https://github.com/rero/rero-ils/blob/dev/CONTRIBUTING.rst#get-started point 6.)