Improve wording of labelmap action
Update the wording of the `labelmap` relabel action to make it more
clear that it acts on all the label names, rather than the list provided
by source_labels.
@@ -2471,9 +2471,9 @@ anchored on both ends. To un-anchor the regex, use `.*<regex>.*`.
* `keep`: Drop targets for which `regex` does not match the concatenated `source_labels`.
* `drop`: Drop targets for which `regex` matches the concatenated `source_labels`.
* `hashmod`: Set `target_label` to the `modulus` of a hash of the concatenated `source_labels`.
-* `labelmap`: Match `regex` against all label names. Then copy the values of the matching labels
- to label names given by `replacement` with match group references
- (`${1}`, `${2}`, ...) in `replacement` substituted by their value.
+* `labelmap`: Ignore `source_labels` and match `regex` against all source label names. Then
+ copy the values of the matching labels to label names given by `replacement` with match
+ group references (`${1}`, `${2}`, ...) in `replacement` substituted by their value.
* `labeldrop`: Match `regex` against all label names. Any label that matches will be
removed from the set of labels.
* `labelkeep`: Match `regex` against all label names. Any label that does not match will be
