Yes, every unfamiliar language requires some learning. But I don’t think the bash syntax is particularly approachable.
I searched and picked the first result, but this seems to present what I mean pretty well https://unix.stackexchange.com/questions/248164/bash-if-syntax-confusion which doesn’t even include the alternative if parens https://stackoverflow.com/questions/12765340/difference-between-parentheses-and-brackets-in-bash-conditionals
I find other languages syntaxes much more approachable.
I also mentioned the magic variable expansion operators. https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html
Most other languages are more expressive.
How do you intend to present your GitHub portfolio to your potential employers? Nobody’s going to do a full, in-depth, or even basic analysis of your repos unless maybe with automated tools or what GitHub itself provides.
Your CV and interview are much more important. Solutions [and projects] matter much more than details. Experience and that you can talk about your work or experience is much more important than technical details.
A hash table library doesn’t sound like particularly noteworthy expertise. Adding a dependency and calling simple documented methods on it in a simple, standard behavior manner isn’t noteworthy.
If you’re implementing your own, I wonder if “simply” implies a non-noteworthy implementation, or in-depth exploration of hashing and storage indexing. The latter would be a different project though, putting your other on hold.
I don’t see it making a difference for employers what you pick here specifically.
If you’re interested in implementing one or learning about the technicalities of it go ahead. Otherwise use a library and continue with your project or other interests.
Disclaimer: I’m not in the recruiting space nor do I have that much or recent experience being interviewed/the broader companies hiring processes.