[UNOFFICIAL BUILD] Google / LG Nexus 5X (bullhead) for /e/OS-S

Yes, first install the docker instance for /e/OS version you want. However I prefer the repo way:

For extracting vendor blobs, here are the instructions:
https://wiki.lineageos.org/extracting_blobs_from_zips

The file extract_files.sh is in the device folder of the smartphone eg: device/lge/bullhead
If you have a supported device all needed files (except vendor files which you need to get from eg gibhub/TheMuppets) are available after running breakfast DEVICECODE. For unsupported devices you need to either manually put all files in the respective folders or if there is a manifest.xml can run repo sync.