add editorconfig and editorconfig check

.build.yml

@@ -1,9 +1,13 @@
 image: alpine/edge
 packages:
   - shellcheck
+  - editorconfig-checker
 sources:
   - https://git.sr.ht/~mil/sxmo-utils
 tasks:
   - shellcheck: |
       cd sxmo-utils
       shellcheck scripts/*/*
+  - editorconfig-check: |
+      cd sxmo-utils
+      ec

.editorconfig

@@ -0,0 +1,14 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+indent_style = tab
+max_line_length = 72
+spaces_around_operators = true
+charset = utf-8
+trim_trailing_whitespace = true