Add editor configs

Add .editorconfig, .vscode and .gitattributes configs to make editors
and tools aware that the files use unix line indeings and are indentent
with tabs.

.vscode/settings.json

@@ -0,0 +1,20 @@
+{
+	"explorer.fileNesting.enabled": true,
+	"explorer.fileNesting.patterns": {
+		"tsconfig.json": "tsconfig.*.json, env.d.ts",
+		"vite.config.*": "jsconfig*, vitest.config.*, cypress.config.*, playwright.config.*",
+		"package.json": "package-lock.json, bun.lockb, pnpm*, .yarnrc*, yarn*, .eslint*, eslint*, .prettier*, prettier*"
+	},
+	"editor.codeActionsOnSave": {
+		"source.fixAll": "explicit"
+	},
+	"editor.detectIndentation": false,
+	"editor.insertSpaces": false,
+	"files.eol": "\n",
+	"files.insertFinalNewline": true,
+	"files.trimFinalNewlines": true,
+	"[yaml]": {
+		"editor.indentSize": 2,
+		"editor.insertSpaces": true,
+	},
+}