Device wiki pages on Lineage are enough. The process isn't complicated, and boils down to a handful of steps after downloading the requisite files. Off the top off my head:
1. Enable ADB on device
2. Unlock the bootloader
3. Use fastboot to install TWRP
4. Boot into recovery and use TWRP to complete installation from zip files (Android ROM, Google apps)
I'm tinkering with 3D-printed slide-out landscape keyboards, but there are a lot of commercially available bluetoth keyboard cases.
1. The 2014 Nexus 7 packs a FHD screen compare to the 720 in TFA. Its display is shockingly crisp for an 8-year-old device