1. Bump shfmt to v3.5.1. Release notes:
https://github.com/mvdan/sh/releases
2. Since shfmt v3.5.0, specifying -l bash (or -l bats) is no longer
necessary. Therefore, we can use shfmt to find all the files.
Add .editorconfig to ignore vendor subdirectory.
3. Use shfmt docker image, so that we don't have to install anything
explicitly. This greatly simplifies the shfmt CI job. Add
localshfmt target so developers can still use a local shfmt binary
when necessary.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin