Add board NUCLEO L412RB-P

[gudnimg]

• Name: ST Nucleo L412RB-P
• Link to all relevant information:

• https://www.st.com/en/evaluation-tools/nucleo-l412rb-p.html (Here you can find User manual, schematics)
• I bought it here: https://www.digikey.com/en/products/detail/stmicroelectronics/NUCLEO-L412RB-P/9656230

[gudnimg]

I would add it myself but saw in the issue template I should wait for v2.0.0

[fpistm]

Hi @GunZi200
I've added this request to the new variant request list #722.
2.0.0 will come soon.