chore(docs): add cli flag to args.md

Signed-off-by: Bukowa <gitbukowa@gmail.com>

website/docs/usage/args.md

@@ -39,6 +39,7 @@ git-cliff [FLAGS] [OPTIONS] [--] [RANGE]
 -p, --prepend <PATH>             Prepends entries to the given changelog file [env: GIT_CLIFF_PREPEND=]
 -o, --output [<PATH>]            Writes output to the given file [env: GIT_CLIFF_OUTPUT=]
 -t, --tag <TAG>                  Sets the tag for the latest version [env: GIT_CLIFF_TAG=]
+    --bump-initial-tag <TAG>     Sets the initial tag (version) to be set if no tag is found [env: GIT_CLIFF_BUMP_INITIAL_TAG=]
 -b, --body <TEMPLATE>            Sets the template for the changelog body [env: GIT_CLIFF_TEMPLATE=]
 -s, --strip <PART>               Strips the given parts from the changelog [possible values: header, footer, all]
     --sort <SORT>                Sets sorting of the commits inside sections [default: oldest] [possible values: oldest, newest]