Increase content font size

[gnprice]

This is a sub-issue of:

• Convert message list to new, 2023+ design #157

Currently the app's font size for plain text in message bodies is 14px. That dates from the early prototype phase, when I was copying web's design meticulously (to demonstrate that we could).

The corresponding size in the zulip-mobile legacy RN app is 16px, I believe.

The corresponding size in @terpimost's design in Figma is 17px. For example, see here.

So we should increase the size, either to 16px or 17px.

If we're unsure which of those sizes to prefer, we could add a setting (even if only for the beta period) — that would make it easy for beta users to experiment with the different values and take crisp apples-to-apples pairs of screenshots for discussion.

Chat thread: https://chat.zulip.org/#narrow/stream/48-mobile/topic/density.20in.20message.20list/near/1733351

[vijay-kesanakurthi]

I want to work on this, to get a better understanding of the project for GSOC.

[gnprice]

@vijay-kesanakurthi Ah, we should have marked this sooner — this is actually an issue that a member of the core team is planning to take care of within the next week. I'll mark it as assigned now.

There are plenty of other issues on our project board, though, that don't have anyone assigned, so I'd encourage browsing through those. And if you haven't already, please take a look at the Zulip project's guide for picking an issue to work on: https://zulip.readthedocs.io/en/latest/contributing/contributing.html#picking-an-issue-to-work-on