README: add instruction to run Vale on a subset

make stylecheck runs Vale on the whole documentation which can be long
and reports a lot of errors/warnings. We can run Vale on a subset using
the VALEDOCS variable, so update documentation to highlight it.

(From yocto-docs rev: e75064520f86c9fd674acff3dd16c88dcc489ba6)

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: Antonin Godard <antonin.godard@bootlin.com>
Tested-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 262237f72534c983e178231cb6839ed69709c443)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/documentation/README b/documentation/README
index b60472fcbf..a7138c40e2 100644
--- a/documentation/README
+++ b/documentation/README
@@ -165,6 +165,14 @@ To run Vale:
 
  $ make stylecheck
 
+Style checking the whole documentation might take some time and generate a
+lot of warnings/errors, thus one can run Vale on a subset of files or
+directories:
+
+  $ make stylecheck VALEDOCS=<file>
+  $ make stylecheck VALEDOCS="<file1> <file2>"
+  $ make stylecheck VALEDOCS=<dir>
+
 Link checking the Yocto Project documentation
 =============================================