feat(version): use exit code for check to indicate out-of-date versions

It can be handy to have an exit code that allows better status
indication or chaining.

On exit, return one of the following codes:

- 0: Normal exit condition, all checked versions are up-to-date
- 1: Unknown cause of failure
- 2: Normal exit condition, but there are out-of-date versions
- 3: Failed to run some version checks

Component: pkgctl version check
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/doc/man/pkgctl-version-check.1.asciidoc b/doc/man/pkgctl-version-check.1.asciidoc
index 3113afa..fa5401f 100644
--- a/doc/man/pkgctl-version-check.1.asciidoc
+++ b/doc/man/pkgctl-version-check.1.asciidoc
@@ -36,6 +36,23 @@ Options
 *-h, --help*::
 	Show a help text
 
+Errors
+------
+
+On exit, return one of the following codes:
+
+*0*::
+	Normal exit condition, all checked versions are up-to-date
+
+*1*::
+	Unknown cause of failure
+
+*2*::
+	Normal exit condition, but there are out-of-date versions
+
+*3*::
+	Failed to run some version checks
+
 See Also
 --------