Merge bitcoin#21711: guix: Add full installation and usage documentation

fac4814 doc/release-process: Add torrent creation details (Carl Dong)
5d24cc3 guix/INSTALL: Guix installs init scripts in libdir (Carl Dong)
5da2ee4 guix/INSTALL: Add coreutils/inotify-dir-recreate troubleshooting (Carl Dong)
318c607 guix: Adapt release-process.md to new Guix process (Carl Dong)
fcab35b guix-attest: Produce and sign normalized documents (Carl Dong)
c2541fd guix: Overhaul README (Carl Dong)
46ce6ce tree-wide: Rename gitian-keys to builder-keys (Carl Dong)
fc4f844 guix: Update various check_tools lists (Carl Dong)
263220a guix: Check for a sane services database (Carl Dong)

Pull request description:

  Based on: bitcoin#21462

  Keeping the README in one file so that it's easy to search through. Will add more jumping links later so navigation is easier.

  Current TODOs:
  - [x] Shell installer option: prompt user to re-login for `/etc/profile.d` entry to be picked up
  - [x] Binary tarball option: prompt user to create `/etc/profile.d` entry and re-login
  - [x] Fanquake docker option: complete section
  - [x] Arch Linux AUR option: prompt to start `guix-daemon-latest` unit after finishing "optional setup" section
  - [x] Building from source option: Insert dependency tree diagram that I made
  - [x] Building from source option: redo sectioning, kind of a mess right now
  - [x] Optional setup: make clear which parts are only needed if building from source
  - [x] Workaround 1 for GnuTLS: perhaps mention how to remove Guix build farm's key
  - [x] Overall (after everything): Make the links work.

  Note to self: wherever possible, tell user how to check that something is true rather than branching by installation option.

ACKs for top commit:
  fanquake:
    ACK fac4814 - going to go ahead and merge this now. It's a lot of documentation, and could probably be nit-picked / improved further, however, that can continue over the next few weeks. I'm sure more (backportable) improvements / clarifications will be made while we progress through RCs towards a new release.

Tree-SHA512: dc46c0ecdfc67c7c7743ca26e4a603eb3f54adbf81be2f4c1f4c20577ebb84b5250b9c9ec89c0e9860337ab1c7cff94d7963c603287267deecfe1cd987fa070a

Author: fanquake

contrib/README.md

@@ -29,8 +29,8 @@ All other packaging related files can be found in the [bitcoin-core/packaging](h
 ### [Gitian-descriptors](/contrib/gitian-descriptors) ###
 Files used during the gitian build process. For more information about gitian, see the [the Bitcoin Core documentation repository](https://github.com/bitcoin-core/docs).
 
-### [Gitian-keys](/contrib/gitian-keys)
-PGP keys used for signing Bitcoin Core [Gitian release](/doc/release-process.md) results.
+### [Builder keys](/contrib/builder-keys)
+PGP keys used for signing Bitcoin Core [release](/doc/release-process.md) results.
 
 ### [MacDeploy](/contrib/macdeploy) ###
 Scripts and notes for Mac builds.

contrib/gitian-keys/README.md renamed to contrib/builder-keys/README.md

@@ -1,10 +1,10 @@
-## PGP keys of Gitian builders and Developers
+## PGP keys of builders and Developers
 
-The file `keys.txt` contains fingerprints of the public keys of Gitian builders
-and active developers.
+The file `keys.txt` contains fingerprints of the public keys of builders and
+active developers.
 
 The associated keys are mainly used to sign git commits or the build results
-of Gitian builds.
+of Guix builds.
 
 The most recent version of each pgp key can be found on most pgp key servers.
 
@@ -16,12 +16,12 @@ To fetch the latest version of all pgp keys in your gpg homedir,
 gpg --refresh-keys
 ```
 
-To fetch keys of Gitian builders and active developers, feed the list of
-fingerprints of the primary keys into gpg:
+To fetch keys of builders and active developers, feed the list of fingerprints
+of the primary keys into gpg:
 
 ```sh
 while read fingerprint keyholder_name; do gpg --keyserver hkp://subset.pool.sks-keyservers.net --recv-keys ${fingerprint}; done < ./keys.txt
 ```
 
-Add your key to the list if you provided Gitian signatures for two major or
+Add your key to the list if you provided Guix attestations for two major or
 minor releases of Bitcoin Core.