Adding vectors, dot above, double dot above

[vinix38]

The following were added :

• vectors for all letters, uppercase and lowercase
• dot above for all lowercase letters and a few greek letters
• double dot above for all lowercase letters and a few greek letters

This is more of a suggestion. Feel free to modify this pull request to bring it inline with project requirements.

[vinix38]

When using my phone, shortcuts using • do work properly.
However, using ASCII characters seems sensible to me, as it is easier to use and remember. I have made the changes you envisioned. I have removed dotted Greek letters at the moment, because I am not sure whether they are relevant and how to handle their shortcuts.

[DenverCoder1]

Looks great! Thanks for the contribution 🎉

[DenverCoder1]

When using my phone, shortcuts using • do work properly.

You are right, it seems I put it in wrong when testing. I assumed it was a similar issue to #13 but it seems like even that is working again now in the latest version of Gboard.

Edit: some from #13 are working but it seems like not all of them (eg. parentheses seem to still be broken)