docs: add 7.x publish script

Author: vkarpov15

package.json

@@ -96,6 +96,7 @@
     "docs:prepare:publish:stable": "npm run docs:checkout:gh-pages && npm run docs:merge:stable && npm run docs:clean:stable && npm run docs:generate && npm run docs:generate:search",
     "docs:prepare:publish:5x": "npm run docs:checkout:5x && npm run docs:merge:5x && npm run docs:clean:stable && npm run docs:generate && npm run docs:copy:tmp && npm run docs:checkout:gh-pages && npm run docs:copy:tmp:5x",
     "docs:prepare:publish:6x": "npm run docs:checkout:6x && npm run docs:merge:6x && npm run docs:clean:stable && env DOCS_DEPLOY=true npm run docs:generate && npm run docs:move:6x:tmp && npm run docs:checkout:gh-pages && npm run docs:copy:tmp:6x",
+    "docs:prepare:publish:7x": "npm run docs:checkout:gh-pages && git merge 7.x && npm run docs:clean:stable && npm run docs:generate && npm run docs:generate:search",
     "docs:check-links": "blc http://127.0.0.1:8089 -ro",
     "lint": "eslint .",
     "lint-js": "eslint . --ext .js --ext .cjs",