Rename songbooks -> builder
Add stub Plugin structure
Move server into bin/, fix table name
Revert "Run a single guix-daemon"

This reverts commit 8cfe5a9008d30a3b1249cf7733e60b82eb11d66b.

Failed build run:
build-aux/guix.scm: Categorize specifications
Run a single guix-daemon
Stop using .envrc for perl libs
guix.scm: Move to build-aux/ and use return a manifest instead
server: WIP v0 implementation of email authentication
guix.scm: Add note where lilypond-stable came from
guix.scm: Use upstream TiMidity++ package

There's no need to override the package anymore since the custom input was added
to Guix itself in 3065bf8aa20ac1d13d6eb07707ae67ef88f6359f[0].

[0]: https://git.savannah.gnu.org/cgit/guix.git/commit/?id=3065bf8aa20ac1d13d6eb07707ae67ef88f6359f
server: WIP Start implementing tiny server with Mojolicious
WIP: Use QEMU instead of Vagrant
CI: Uncomment CI steps
.build.yml: Use stable Debian in CI
Disable bloated CI builds
docs: Remove extra header from internals.rst