Add example build runner scripts and config for Zig code completion.

examples/tools/buildifier.sh

@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
+cd "$(bazel info workspace)"
 exec bazel run -- @buildifier_prebuilt//:buildifier "$@"

examples/tools/zls.sh

@@ -1,3 +1,4 @@
 #!/bin/bash
 cd "$(dirname "${BASH_SOURCE[0]}")"
-exec bazel run --config=silent @zml//third_party/zls:zls -- "${@}"
+cd "$(bazel info workspace)"
+exec bazel run -- @zml//third_party/zls:zls "${@}"

examples/zls.build.json

@@ -1,8 +1,2 @@
 {
-  "build_options": [
-    {
-      "name": "cmd",
-      "value": "bazel run @zml//:completion"
-    }
-  ]
 }