docs: remove references to %% prefix operator

also cleanup the table of contents

doc/langref.html.in

@@ -1018,21 +1018,6 @@ const unwrapped = value catch 1234;
 unwrapped == 1234</code></pre>
           </td>
         </tr>
-        <tr>
-          <td><pre><code class="zig">%%a</code></pre></td>
-          <td>
-            <ul>
-              <li><a href="#errors">Error Unions</a></li>
-            </ul>
-          </td>
-          <td>Equivalent to:
-            <pre><code class="zig">a catch unreachable</code></pre>
-          </td>
-          <td>
-            <pre><code class="zig">const value: %u32 = 5678;
-%%value == 5678</code></pre>
-          </td>
-        </tr>
         <tr>
           <td><pre><code class="zig">a and b<code></pre></td>
           <td>
@@ -1260,7 +1245,7 @@ const ptr = &amp;x;
       {#header_close#}
       {#header_open|Precedence#}
       <pre><code>x() x[] x.y
-!x -x -%x ~x *x &amp;x ?x %x %%x ??x
+!x -x -%x ~x *x &amp;x ?x %x ??x
 x{}
 * / % ** *%
 + - ++ +% -%
@@ -5218,9 +5203,8 @@ const c = @cImport({
       <p>
       You can mix Zig object files with any other object files that respect the C ABI. Example:
       </p>
-      {#header_close#}
-      {#header_open|base64.zig#}
-      {#code_begin|obj#}
+      <p class="file">base64.zig</p>
+      {#code_begin|syntax#}
 const base64 = @import("std").base64;
 
 export fn decode_base_64(dest_ptr: &u8, dest_len: usize,
@@ -5234,8 +5218,7 @@ export fn decode_base_64(dest_ptr: &u8, dest_len: usize,
     return decoded_size;
 }
       {#code_end#}
-      {#header_close#}
-      {#header_open|test.c#}
+      <p class="file">test.c</p>
       <pre><code class="cpp">// This header is generated by zig from base64.zig
 #include "base64.h"
 
@@ -5252,8 +5235,7 @@ int main(int argc, char **argv) {
 
     return 0;
 }</code></pre>
-      {#header_close#}
-      {#header_open|build.zig#}
+      <p class="file">build.zig</p>
       {#code_begin|syntax#}
 const Builder = @import("std").build.Builder;