Add clarification on what exactly the preset sync settings do

[Korb]

Pre-Submission checklist

• There is no existing issue that already asks for this feature.
  
• The feature already exists in rclone (on your PC or in Termux)
• I am prepared to help make this feature

What version of Round Sync are you using (About -> App version)?

• App Version 2.5.6
• Rclone Version 1.68.0-extract

What problem are you trying to solve?

Currently, the Create a new Task screen has a Direction parameter that can take the following values:

1. Sync local to remote
2. Sync remote to local
3. Copy local to remote
4. Copy remote to local

Only the following text is provided as an explanation:

Synchronize files from local storage to remote storage. Any files that are not present locally will be deleted from the remote storage. Only affects the files on the remote storage.

It is not entirely clear to me how exactly each of the options works in case of differences in the synced folders, such as the presence or absence of files and folders in the source or destination folder, or differences in creation/modification dates, or in case of file sizes.

For example, below I will quote a list of predefined sync options, from which I understand what exactly each of the options does, and I do not have questions like the above:

1. Mirror A → B (incremental): This is a mono-directional (one way) preconfgured synchronization which copies all the new and modifed fles/directories from DirA to DirB. A fle/directory in DirB which does not correspond to a fle/directory in DirA is marked as redundant and will be deleted. DirB is exactly the same as DirA after the synchronization.
2. Mirror B → A (incremental): Same as 'Mirror A → B (incremental)' with DirA and DirB swapped.
3. Synchronize A ⇆ B (incremental): This is a bi-directional (two way) preconfgured synchronization which copies all the new and modifed fles/directories from DirA to DirB and from DirB to DirA. All redundant fles in DirA/DirB (according to each other) will be deleted after the synchronization. DirA and DirB will be exactly the same after the synchronization. If you select this mode, you may also defne the confict resolution mode in the confict resolution tab.
4. Synchronize A ⇆ B (custom): Same as ‘Synchronize A ⇆ B (incremental)’ except some tabs get enabled in which you may set up your own options to defne the synchronization behavior as you may wish.
5. Backup A → B (full): This is a full copy preconfgured synchronization which will copy all fles/directories one-by-one from DirA to DirB. This mode is useful when you want to make a complete backup of DirA.
6. Restore B → A (full): This is a full copy preconfgured synchronization which will copy all fles/directories one-by-one from DirB to DirA. This mode is useful when you want to restore a backup to DirA.
7. Contribute A → B (incremental): This is a mono-directional (one way) preconfgured synchronization which copies all the new fles/directories from DirA to DirB. No fle is deleted from DirB in this mode.
8. Contribute B → A (incremental): Same as 'Contribyte A → B (incremental)'. with DirA and DirB swapped.
9. Synchronize A → B (custom): This is a mono-directional (one way) custom synchronization from DirA to DirB. If you select this mode, some tabs get enabled in which you may set up your own options to defne the synchronization behavior as you may wish.
10. Synchronize B → A (custom): Same as 'Synchronize A → B (custom)' with DirA and DirB swapped.

What should Round Sync be able to do differently to help with this problem?

• A round button with a question mark that, when clicked, displays a tooltip describing all the items in the list.
• After selecting an option, its description is displayed below it.
• A built-in help article within the user manual.