Add mention of "caching" issue to Exporting for Web documentation

[awardell]

Describe the project you are working on

Building a project for web.

Describe the problem or limitation you are having in your project

When using the "Remote Debug" launcher from the editor, I began receiving an old, cached version of a different project. I had not experienced this issue before with (older versions of) Godot, so I didn't realize what the problem was. I tried deleting the files in /AppData/Local/Godot/web. I tried compiling new export templates. I read all over the docs to see if I was missing something. Finally I happened to look at the storage cache in Firefox's dev tools, and tried deleting that. That solved the issue.

Clearly I'm not the greatest web dev, but then I would argue probably neither are most of Godot's users. There seem to be numerous issues like godotengine/godot#75743 popping up.

There was a PR godotengine/godot#56841 that seems like it would have fixed this issue, but maybe had some other problems and it never made it through.

In that issue I came across this comment godotengine/godot#75743 (comment) which greatly assisted me, but it's frustrating that I spent so long banging my head before finding it.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Until the issues surrounding caching are resolved, there should be some mention of the issue and the workaround in the documentation on the Exporting for the Web page and on maybe the One-click deploy page. The workaround described in the comment godotengine/godot#75743 (comment) is currently crucial for using one-click deploy, and when fully deploying it is important to understand the need to get your website to serve the latest version. This info could perhaps be in another "! Attention" box.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

see above.

If this enhancement will not be used often, can it be worked around with a few lines of script?

NA

Is there a reason why this should be core and not an add-on in the asset library?

NA