Merge #13605: Docs: corrected text to reflect new[er] process of spec…

…ifying fingerprints

8564435 Corrected text to reflect new[er] process of specifying fingerprints instead of individual keys. (Jeff Frontz)

Pull request description:

  More accurately reflects the contents of the directory and keys.txt (i.e., contains fingerprints of keys instead of actual keys).

Tree-SHA512: c8e70e6d905faa348b269cb39c72a1b4b525bc00445e4a5ad4204f54925da4b055444828e62c45c6f8798fe9d23526eb7779d9b2edcf22679441586a558d0d05

contrib/gitian-keys/README.md

@@ -1,9 +1,10 @@
 ## PGP keys of Gitian builders and Developers
 
-The keys.txt contains the public keys of Gitian builders and active developers.
+The file `keys.txt` contains fingerprints of the public keys of Gitian builders
+and active developers.
 
-The keys are mainly used to sign git commits or the build results of Gitian
-builds.
+The associated keys are mainly used to sign git commits or the build results
+of Gitian builds.
 
 The most recent version of each pgp key can be found on most pgp key servers.