add zhihu social link

_config.yml

@@ -40,7 +40,7 @@ footer-links:
   #weibo: frommidworld #请输入你的微博个性域名 https://www.weibo.com/<thispart>
   behance: # https://www.behance.net/<username>
   dribbble:
-  #zhihu_username: ll-chen-2
+  zhihu: ll-chen-2
   email: lemonchann@foxmail.com
   facebook:
   flickr:
@@ -53,7 +53,7 @@ footer-links:
   stackoverflow: # your stackoverflow profile, e.g. "users/50476/bart-kiers"
   tumblr: # https://<username>.tumblr.com
   #twitter: frommidworld
-  youtube: # channel/<your_long_string> or user/<user-name>
+  youtube:
 
 # Text under the icons in footer
 footer-text: Copyright (c) 2014 lemonchann

_includes/svg-icons.html

@@ -25,6 +25,10 @@
   <li><a href="https://www.flickr.com/{{ site.footer-links.flickr }}" class="icon-11 flickr" title="Flickr"><svg viewBox="0 0 512 512"><path d="M400 32H48C21.5 32 0 53.5 0 80v352c0 26.5 21.5 48 48 48h352c26.5 0 48-21.5 48-48V80c0-26.5-21.5-48-48-48zM144.5 319c-35.1 0-63.5-28.4-63.5-63.5s28.4-63.5 63.5-63.5 63.5 28.4 63.5 63.5-28.4 63.5-63.5 63.5zm159 0c-35.1 0-63.5-28.4-63.5-63.5s28.4-63.5 63.5-63.5 63.5 28.4 63.5 63.5-28.4 63.5-63.5 63.5z"/></svg><!--[if lt IE 9]><em>Flickr</em><![endif]--></a></li>
   {% endif %}
 
+  {% if site.footer-links.zhihu %}
+  <li><a href="https://zhihu.com/people/{{ site.footer-links.zhihu }}" class="icon-2 zhihu" title="ZhiHu"><svg viewBox="0 0 600 600"><path d="M170.54 148.13v217.54l23.43.01 7.71 26.37 42.01-26.37h49.53V148.13H170.54zm97.75 193.93h-27.94l-27.9 17.51-5.08-17.47-11.9-.04V171.75h72.82v170.31zm-118.46-94.39H97.5c1.74-27.1 2.2-51.59 2.2-73.46h51.16s1.97-22.56-8.58-22.31h-88.5c3.49-13.12 7.87-26.66 13.12-40.67 0 0-24.07 0-32.27 21.57-3.39 8.9-13.21 43.14-30.7 78.12 5.89-.64 25.37-1.18 36.84-22.21 2.11-5.89 2.51-6.66 5.14-14.53h28.87c0 10.5-1.2 66.88-1.68 73.44H20.83c-11.74 0-15.56 23.62-15.56 23.62h65.58C66.45 321.1 42.83 363.12 0 396.34c20.49 5.85 40.91-.93 51-9.9 0 0 22.98-20.9 35.59-69.25l53.96 64.94s7.91-26.89-1.24-39.99c-7.58-8.92-28.06-33.06-36.79-41.81L87.9 311.95c4.36-13.98 6.99-27.55 7.87-40.67h61.65s-.09-23.62-7.59-23.62v.01zm412.02-1.6c20.83-25.64 44.98-58.57 44.98-58.57s-18.65-14.8-27.38-4.06c-6 8.15-36.83 48.2-36.83 48.2l19.23 14.43zm-150.09-59.09c-9.01-8.25-25.91 2.13-25.91 2.13s39.52 55.04 41.12 57.45l19.46-13.73s-25.67-37.61-34.66-45.86h-.01zM640 258.35c-19.78 0-130.91.93-131.06.93v-101c4.81 0 12.42-.4 22.85-1.2 40.88-2.41 70.13-4 87.77-4.81 0 0 12.22-27.19-.59-33.44-3.07-1.18-23.17 4.58-23.17 4.58s-165.22 16.49-232.36 18.05c1.6 8.82 7.62 17.08 15.78 19.55 13.31 3.48 22.69 1.7 49.15.89 24.83-1.6 43.68-2.43 56.51-2.43v99.81H351.41s2.82 22.31 25.51 22.85h107.94v70.92c0 13.97-11.19 21.99-24.48 21.12-14.08.11-26.08-1.15-41.69-1.81 1.99 3.97 6.33 14.39 19.31 21.84 9.88 4.81 16.17 6.57 26.02 6.57 29.56 0 45.67-17.28 44.89-45.31v-73.32h122.36c9.68 0 8.7-23.78 8.7-23.78l.03-.01z"/></svg><!--[if lt IE 9]><em>YouTube</em><![endif]--></a></li>
+  {% endif %}
+  
   {% if site.footer-links.github %}
   <li><a href="https://github.com/{{ site.footer-links.github }}" class="icon-13 github" title="GitHub"><svg viewBox="0 0 512 512"><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg><!--[if lt IE 9]><em>GitHub</em><![endif]--></a></li>
   {% endif %}