Feature/english (#381)

* perf[navbar]: set langSelect to component && refine errorLog component

* feat[login]:add 18n to login form

* fix[pagination]: fixed when selected page-sizes

* perf[i18n]:dashboard document svg permission

* perf[charts]: perf effect

* perf[i18n]:excel && zip

* perf[i18n]: table && errorLog && theme

* perf[i18n]: components

* perf[i18n]: direct use $t

* perf[i18n]: complex-table

* update README.md

* update README.md 📘

* perf[i18n]: refine code comments

src/styles/element-ui.scss

@@ -27,6 +27,13 @@
    }
  }
 
+ .fixed-width{
+  .el-button--mini{
+    padding: 7px 10px;
+    width: 60px;
+  }
+ }
+
  .status-col {
    .cell {
      padding: 0 10px;

src/styles/index.scss

@@ -102,7 +102,8 @@ code {
   margin-bottom: 20px;
   display: block;
   line-height: 36px;
-  font-size: 14px;
+  font-size: 15px;
+  font-family: "Source Sans Pro", "Helvetica Neue", Arial, sans-serif;
   a {
     color: #337ab7;
     cursor: pointer;