Update recommendations for installing Console Arcs

[drojf]

Currently we have this on the console arcs install page in the installer:

Given this, it would make sense to also have a warning on the Chapter 4 install page telling you to make a backup.

Also, the instructions that you could install to a copy of the game folder might interfere with steam's cloud sync (I'm guessing it would prevent it from working?), so perhaps that recommendation is not the best without added instructions.

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Perhaps the simpler/safest way is to just tell the user to fully delete chapter 4, then re-install the unmodded game. The installer can check whether the game is already modded and show a warning if that is the case. Using this method, we also dont' need to have a preemptive warning on Chapter 4.

Also see #129

[drojf]

If it's 100% safe to install over the top of the existing chapter 4, then everything can be further simplified (just need to warn the user it would overwrite the existing chapter 4 mod).

We actually state this on the wiki: https://07th-mod.com/wiki/Higurashi/Manual-Installation/

But on this page it says something different? https://07th-mod.com/wiki/Higurashi/Higurashi-Getting-started/

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I realized there is one more case to take care of, which is if the user wishes to have all chapters installed at the same time. In that case, the must have a duplicate Chapter 4 somewhere on their computer.

[drojf]

Please also see #33 which is a dup of this issue (and close 33 when this is closed)