Set register command

[sjernigan]

I've added the ability to set a single register. I needed an extremely simple 595 7-segment library and this mostly fits the bill, thanks.

[jasonwbarnett]

Hi @Simsso,

Thank you for maintaining this great library—it's been incredibly useful in my projects. I noticed this pull request and wanted to say that the setRegister method seems like a valuable addition, especially for scenarios where controlling individual shift registers in a chain is necessary.

I believe it aligns well with the library's design principles and could benefit its users. If there's anything I can do to help with testing, documentation, or further reviewing this PR, I'd be happy to assist.

Looking forward to your thoughts on this.

[jasonwbarnett]

Suggested change

	// digitalVAlues is a uint8_t, reg is a uint8_t from 0 to Size -1
	// digitalValues is a uint8_t, reg is a uint8_t from 0 to Size -1

[jasonwbarnett]

@Simsso Can you apply this patch before merging to fix the case?

[Simsso]

Thanks, @jasonwbarnett. Did you have a chance to test the new function? If so, I'd be happy to submit the PR. We only need to increment the minor library version.

[jasonwbarnett]

Hi @Simsso,

Thank you for your quick response. I’ve tested the setRegister method, and it works perfectly in my setup for controlling individual shift registers in a chain. I didn’t encounter any issues during my tests.

[jasonwbarnett]

Hi! I wanted to gently nudge and see if there is anything I need to do to get this merged. Thanks for your time.