Add editorconfig and markdown formatter script

.editorconfig

@@ -0,0 +1,17 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
+insert_final_newline = true
+max_line_length = 120
+
+[*.rs]
+indent_size = 4
+max_line_length = 100
+
+[*.{md,mdx}]
+max_line_length = 100

scripts/format.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -o errexit -o nounset -o pipefail
+command -v shellcheck >/dev/null && shellcheck "$0"
+
+# Running with -c makes the script only validate instead of editing in place.
+op="write"
+while getopts c option; do
+  case "${option}" in
+  c) op="check" ;;
+  *) ;;
+  esac
+done
+
+npx [email protected] --$op --no-config "./src/**/*.md" "./src/**/*.mdx"