[Feat] Add battery charging

[vicgwee]

• [ ] Find suitable Lipo battery
• [ ] Test charging from OLA
• [ ] Test battery life

[vicgwee]

Lipo battery connector: PH2.0

Local sources of Lipo batteries: https://www.rotor.sg/home/2478-1s-37v-220mah-35c-lipo-battery-for-armor-blue-shark.html https://www.rotor.sg/home/456-37v-300mah-lipo-battery-with-white-jst-ph125-connector-for-tk115-drone.html https://www.sgbotic.com/index.php?dispatch=products.view&product_id=1009 https://www.singahobby.com/index.php/jumper-1-cell-300mah-lipo-for-x68t-3-7v.html -- cheapest, will probably get from here

[vicgwee]

Done!