Bad line breaks in both UG and DG

[nus-pe-bot]

Note from the teaching team: This bug was reported during the Part II (Evaluating Documents) stage of the PE. You may reject this bug if it is not related to the quality of documentation.

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Headers should always stick to the text beneath instead of being at the bottom of the page, sometimes even non-headers should also have a page break, see below for an example from UG:

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_{[original: nus-cs2103-AY2021S2/pe-interim#3166] [original labels: severity.Low type.DocumentationBug]}

[JodyLorah]

Team's Response

A purely cosmetic issue but we will accept it.

Duplicate status (if any):

Duplicate of #1134