git: Set some fetch options

Use [compact output][1]:

> In compact output mode, specified with configuration variable
> fetch.output, if either entire <from> or <to> is found in the other
> string, it will be substituted with * in the other string. For
> example, master -> origin/master becomes master -> origin/*.

Automatically prune branches and tags.

Set parallelization to use a value set by git as otherwise it defaults
to 1.

[1]: git-fetch(1)

.config/git/config

@@ -35,6 +35,11 @@
 	tool = nvimdiff
 [difftool "meld"]
 	path = /usr/bin/meld
+[fetch]
+	output = compact
+	prune = true
+	pruneTags = true
+	parallel = 0
 [gpg]
 	program = gpg.loopback
 [init]