Minor changes to the Spanish translation

[nubesurrealista]

This PR simply adjusts the Spanish strings for greater consistency.

Currently, some phrases are too formal or redundant. This minor adjustment simply changes the tone and translation of some words.

[nubesurrealista]

I also noticed that the strings have lines that we don't currently use, as they are from features I was using in my fork taken from PRs from the Fluent Reader community: Feed delay and translate.

I think it would be better to remove them until we decide whether we want to integrate those features. There is already a PR for web page translation, but we haven't decided what to do with it yet, so maybe the string for that feature shouldn't be there.

[CrystalSplitter]

Thanks!

[CrystalSplitter]

I think it would be better to remove them until we decide whether we want to integrate those features. There is already a PR for #5, but we haven't decided what to do with it yet, so maybe the string for that feature shouldn't be there.

Perhaps. I'm fine with keeping both. Not like translations go bad, and sometimes they can be re-used. Up to you.

[nubesurrealista]

I'll do a merge as it is now, maybe later we'll have to change it in the future. Or not, maybe those two features will be in the future.