graphql: Add -backend suffix to the plugin directory

plugins/graphql is a backend plugin published at @backstage/plugin-graphql-backend
When exploring the repository, I got confused to find only plugins/graphql since backend plugins are supposed to have the -backend suffix

Signed-off-by: Himanshu Mishra <himanshu@orkohunter.net>

plugins/graphql-backend/package.json

@@ -0,0 +1,59 @@
+{
+  "name": "@backstage/plugin-graphql-backend",
+  "description": "An experimental Backstage backend plugin for GraphQL",
+  "version": "0.1.9",
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "license": "Apache-2.0",
+  "publishConfig": {
+    "access": "public",
+    "main": "dist/index.cjs.js",
+    "types": "dist/index.d.ts"
+  },
+  "homepage": "https://backstage.io",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/backstage/backstage",
+    "directory": "plugins/graphql-backend"
+  },
+  "keywords": [
+    "backstage",
+    "graphql"
+  ],
+  "scripts": {
+    "start": "backstage-cli backend:dev",
+    "build": "backstage-cli backend:build",
+    "lint": "backstage-cli lint",
+    "test": "backstage-cli test",
+    "prepack": "backstage-cli prepack",
+    "postpack": "backstage-cli postpack",
+    "clean": "backstage-cli clean"
+  },
+  "dependencies": {
+    "@backstage/backend-common": "^0.9.0",
+    "@backstage/config": "^0.1.8",
+    "@backstage/plugin-catalog-graphql": "^0.2.12",
+    "@graphql-modules/core": "^0.7.17",
+    "@types/express": "^4.17.6",
+    "apollo-server": "^2.16.1",
+    "apollo-server-express": "^2.16.1",
+    "express": "^4.17.1",
+    "express-promise-router": "^4.1.0",
+    "graphql": "^15.3.0",
+    "helmet": "^4.0.0",
+    "reflect-metadata": "^0.1.13",
+    "winston": "^3.2.1",
+    "yn": "^4.0.0"
+  },
+  "devDependencies": {
+    "@backstage/cli": "^0.7.0",
+    "@types/supertest": "^2.0.8",
+    "eslint-plugin-graphql": "^4.0.0",
+    "msw": "^0.29.0",
+    "supertest": "^6.1.3"
+  },
+  "files": [
+    "dist",
+    "schema.gql"
+  ]
+}