chore: add .editorconfig

.editorconfig

@@ -0,0 +1,11 @@
+[{*.sh,*.bash,*.zsh,siren}]
+indent_style = space
+indent_size = 2
+
+# shfmt options
+shell_variant = bash       # like -ln bash
+binary_next_line = false   # like -bn
+switch_case_indent = true  # like -ci
+space_redirects = true     # like -sr
+keep_padding = false       # like -kp
+function_next_line = false # like -fn