Rewrite application in TypeScript

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false

.eslintignore

@@ -0,0 +1,3 @@
+templates/**
+bin/**
+coverage/**

.eslintrc.json

@@ -0,0 +1,14 @@
+{
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "project": "./tsconfig.all.json",
+    // Memory leak when lots of files exist, or lots of files are being added.
+    // This can occur when running the linter while `./script/test` is adding a
+    // bunch of new files.
+    //
+    // See: https://github.com/typescript-eslint/typescript-eslint/issues/1080
+    "noWatch": true
+  },
+  "plugins": ["@typescript-eslint"],
+  "extends": ["plugin:@typescript-eslint/recommended"]
+}

.gitignore

@@ -1,15 +1,22 @@
 # Dependencies
 node_modules
 
-# Log files
+# Output folder
+bin
+
+# Logs
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 debug.log
 
-# Lockfiles
-package-lock.json
+# Yarn lockfile. Use package-lock.json instead.
 yarn.lock
 
-# Temporary directory for testing
+# Test-related generated folders
 tmp
+coverage
+
+# Miscellaneous
+.DS_Store
+Thumbs.db