Add missing dev dependencies

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

composer.json

@@ -2,7 +2,9 @@
     "name": "nextcloud/files_texteditor",
     "type": "project",
     "require-dev": {
-        "phpunit/phpunit": "^9.5"
+        "phpunit/phpunit": "^9.5",
+        "vimeo/psalm": "^4.27",
+        "nextcloud/coding-standard": "^1.0"
     },
     "license": "AGPL",
     "authors": [
@@ -11,8 +13,7 @@
             "email": "jus@bitgrid.net"
         }
     ],
-    "require": {},
-	"scripts": {
+    "scripts": {
 		"lint": "find . -name \\*.php -not -path './vendor/*' -not -path './build/*' -print0 | xargs -0 -n1 php -l",
 		"cs:check": "php-cs-fixer fix --dry-run --diff",
 		"cs:fix": "php-cs-fixer fix",