Add plugins: hexo-yam and hexo-nofollow (hexojs#797)

* Add plugin: hexo-yam

* Add plugin: hexo-nofollow

source/_data/plugins.yml

@@ -2108,3 +2108,22 @@
     - highlight
     - code
     - vim
+- name: hexo-yam
+  description: Yet Another Minifier. Minify and compress html, js and css. Support gzip and brotli compressions.
+  link: https://github.com/weyusi/hexo-yam
+  tags:
+    - filter
+    - minify
+    - html
+    - js
+    - css
+    - compress
+    - gzip
+    - brotli
+- name: hexo-nofollow
+  description: Add SEO-friendly nofollow attribute to all external links in your posts. A more updated version of hexo-autonofollow.
+  link: https://github.com/weyusi/hexo-nofollow
+  tags:
+    - SEO
+    - nofollow
+    - external