docs: Add new inputDigest tagger alias to customTemplate tagger
@@ -167,7 +167,7 @@ it will evaluate `FOO` and `BAR` and use their values to tag the image.
{{< alert >}}
<b>Note</b><br>
-`GIT`, `DATE`, and `SHA` are special built-in component references that will evaluate to the default gitCommit, dateTime, and sha256 taggers, respectively.
+`GIT`, `DATE`, `SHA`, and `INPUT_DIGEST` are special built-in component references that will evaluate to the default gitCommit, dateTime, sha256, and inputDigest taggers, respectively.
Users can overwrite these values by defining a component with one of these names.
{{< /alert >}}
