Fix wrong number in rate limits (#858)

Author: mlejva

apps/web/src/app/(docs)/docs/sandbox/rate-limits/page.mdx

@@ -37,7 +37,7 @@ Here's a limits breakdown table based on the plan:
     </tr>
     <tr>
       <td style={{ fontWeight: 'bold', padding: '8px', borderRight: '2px solid #FFB766', border: '2px solid #FFB766' }}>Concurrent sandboxes</td>
-      <td style={{ textAlign: 'center', padding: '8px', borderRight: '2px solid #FFB766', border: '2px solid #FFB766' }}>10</td>
+      <td style={{ textAlign: 'center', padding: '8px', borderRight: '2px solid #FFB766', border: '2px solid #FFB766' }}>20</td>
       <td style={{ textAlign: 'center', padding: '8px', borderRight: '2px solid #FFB766', border: '2px solid #FFB766' }}>100 - 1,100<b><sup>*</sup></b></td>
       <td style={{ textAlign: 'center', padding: '8px', border: '2px solid #FFB766' }}>Custom</td>
     </tr>
@@ -80,7 +80,7 @@ This also includes requests made to custom ports in the sandbox.
 Number of concurrent sandboxes differs based on the pricing tier.
 
 ### Hobby tier
-**Up to 10 concurrent sandboxes**
+**Up to 20 concurrent sandboxes**
 
 ### Pro tier
 **Starts at 100 concurrent sandboxes**