Glossary - align translated terms

[LukasWallrich]

Currently, there are some misalignments between the glossary versions.

Arabic is missing the following (vs German and English

• decolonisation
• git

English is missing the following (vs German and Arabic)

• boundary condition
• trim and fill

These should probably be added or removed consistently.

Also, we might be missing terms from all versions if the previous dividing line is always formatted as H4 - I could only identify and fix these with reasonable effort by checking for discrepancies between the languages. We have 261 in English which seems reasonable given that Phase 1 was described as having more than 250 entries - but if someone wanted to cross-check in some way, that might be worthwhile.