The search bar present on all pages could be optimised in a number of ways. I would add pagination to limit the amount of results which appear with each search as too many might be overwhelming for the user and it doesn't look as nice when the user has to scroll so much.
As Bootstrap is being used, here are some possible options for this: https://getbootstrap.com/docs/4.0/components/pagination/
The search bar present on all pages could be optimised in a number of ways. I would add pagination to limit the amount of results which appear with each search as too many might be overwhelming for the user and it doesn't look as nice when the user has to scroll so much. As Bootstrap is being used, here are some possible options for this: https://getbootstrap.com/docs/4.0/components/pagination/
Also, filter out results which lead to the same location. I searched 'gpg' and the first two results (https://secure-git.guide/002_GPG-Why-we-use-GPG/ and https://secure-git.guide/002_GPG-Why-we-use-GPG/#gpg-why-we-use-gpg) led to the same page, as well as other results appearing more than once, which is unnecessary. A Set could be used to store unique results which can then be displayed to the user.