Unfortunately every person who writes advice about how to break into the industry tells beginners to contribute to OSS as one way to gain experience/a foot in the door. Most of them explicitly list things like fixing typos as easy ways to get a few under your belt.
I can understand the sentiment - it can be quite an anxious experience for a new dev to try to contribute major changes, so theoretically these are low-risk warm-ups. But I don't think it's good advice. It assumes that any contribution is welcomed by the maintainer, no matter how small (many explicitly claim this) and I don't think that's true. Small changes like that that have no impact on functionality, stability, performance, etc. just seem like they would take time and energy from the maintainer with only very marginal upside.
And unfortunately, it also makes the beginner look like someone who's just trying to pad their github "resume".
I'm not saying that's for sure what's happening here for you but it's certainly a possibility.
This is another reason why it's so unfortunate that wikis have died out. GitHub for its part helped kill them and then salted the earth, too—it's hardly possible to even talk about "wikis" anymore, because it's not clear whether a person is actually referring to a wiki wiki, or "some loose leaf Markdown that exists in a repo somewhere (but it's not necessarily clear where), and that's unlikely to allow direct editing without approval". The latter flies in the face of the very etymology of the word.
(To be fair, the same velocity-diminishing forces are at play in the typical practices for using GitHub to collaborate on code, too, but people are even less sensitive to that than they are about wikis.)
I can understand the sentiment - it can be quite an anxious experience for a new dev to try to contribute major changes, so theoretically these are low-risk warm-ups. But I don't think it's good advice. It assumes that any contribution is welcomed by the maintainer, no matter how small (many explicitly claim this) and I don't think that's true. Small changes like that that have no impact on functionality, stability, performance, etc. just seem like they would take time and energy from the maintainer with only very marginal upside.
And unfortunately, it also makes the beginner look like someone who's just trying to pad their github "resume".
I'm not saying that's for sure what's happening here for you but it's certainly a possibility.