docs: Fix missing dolphin theme (#1960)

Author: sy-records

docs/index.html

@@ -41,6 +41,12 @@
       title="pure"
       disabled
     />
+    <link
+      rel="stylesheet"
+      href="//cdn.jsdelivr.net/npm/docsify@4/lib/themes/dolphin.css"
+      title="dolphin"
+      disabled
+    />
     <style>
       nav.app-nav li ul {
         min-width: 100px;

docs/themes.md

@@ -8,6 +8,7 @@ There is a handful of themes available, both official and community-made. Copy [
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/themes/buble.css" />
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/themes/dark.css" />
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/themes/pure.css" />
+<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/themes/dolphin.css" />
 ```
 <!-- prettier-ignore-end -->
 
@@ -21,6 +22,7 @@ There is a handful of themes available, both official and community-made. Copy [
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/lib/themes/buble.css" />
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/lib/themes/dark.css" />
 <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/lib/themes/pure.css" />
+<link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify/lib/themes/dolphin.css" />
 ```
 <!-- prettier-ignore-end -->
 
@@ -33,6 +35,7 @@ If you have any ideas or would like to develop a new theme, you are welcome to s
   <a data-theme="buble">buble.css</a>
   <a data-theme="dark">dark.css</a>
   <a data-theme="pure">pure.css</a>
+  <a data-theme="dolphin">dolphin.css</a>
 </div>
 
 <style>

index.html

@@ -9,6 +9,7 @@
     <link rel="stylesheet" href="/themes/dark.css" title="dark" disabled />
     <link rel="stylesheet" href="/themes/buble.css" title="buble" disabled />
     <link rel="stylesheet" href="/themes/pure.css" title="pure" disabled />
+    <link rel="stylesheet" href="/themes/dolphin.css" title="dolphin" disabled />
     <style>
       nav.app-nav li ul {
         min-width: 100px;