Multiple period days marked on one period button click

[dydyamotya]

Hello!

The topic was discussed in discord first, here is the explanation from discord message:

My wife likes the UX in My Calendar application, where you can tap once when the period starts and the app will mark N days as period days, so you don't need to mark each day of your period. Will you accept the PR with such a functionality? I'm thinking of option in setting, that if you select only one day, than the application will mark N days, where N is setup in options/settings.

I've added a new setting: user_defined_period_length
If this parameters > 0, then pressing "Period" button will mark this day and following [average period] days as period days. If average can't be calculated the user provided value is used.

I'm open to discussion. I've started with most simple algorithm I could imagine.
I've tried to figure out all the edge cases.

[EmmaTellblom]

Hi @dydyamotya
I was looking at merging this into next version. But there are some weird bugs which I haven't been able to identify just yet. When testing I got that when selecting a day for period, it added 4 days, even though 5 was default value. I had this issue several times, but next day when I tested it again it was 5 days. So it's some sort of inconsistent bug?
And then there is another bug when entering period dates in the past (in my case I have older test data and entered period in december 2025), this made the ovulation prediction to also jump back to december 2025 for some reason. I cant replicate this is current version of Mensinator so I suspect it's something in this fix that introduces it (but I might be wrong, lol).

This PR also introduces a new file [‎.editorconfig] which is not something we want in the repo.

If you'd like you could take a look at these bugs or I can continue to look into them, just let me know! This is a good feature for Mensinator. I will also be looking more into the other PR that you have opened, it's also a great feature. But it will take more time to go through.

[dydyamotya]

Hello!

Sorry, I was busy at last weekend. I'll try to look at bugs and fix'em, probably tomorrow.

Thank you for reply.

[dydyamotya]

Oh, I've just accidently messed things up and lost my commit data when rebasing...
I have local copy at home, will restore this PR at Tuesday.