Add changelog and edit doc for increased builds vCPU on paid

Author: yomna-shousha

src/content/changelog/workers/2025-09-07-builds-increased-cpu-paid.mdx

@@ -0,0 +1,19 @@
+---
+title: Increased vCPU for Workers Builds on paid plans
+description: Increased the available vCPU for Workers Builds from 2 to 4 vCPUs for paid plans, improving build performance and parallel processing capabilities.
+  - workers
+date: 2025-09-07
+---
+We recently [increased the available disk space](/changelog/2025-08-04-builds-increased-disk-size/) from 8 GB to 20 GB for **all** plans. Building on that improvement, we’re now doubling the CPU power available for paid plans — from 2 vCPU to **4 vCPU**.  
+
+These changes continue our focus on making [Workers Builds](/workers/ci-cd/builds/) faster and more reliable. We’re monitoring usage closely and exploring bringing this to Free soon.
+
+| Metric     | Free Plan | Paid Plans |
+|------------|-----------|------------|
+| CPU |  2 vCPU  |  **4 vCPU**  |
+
+## What you get
+- **Improved builds**: Even single-threaded workloads benefit from reduced CPU contention and smoother scheduling on our container platform  
+- **Better parallel processing**: Multi-threaded tools and processes can now utilize more cores  
+
+All other [build limits](/workers/ci-cd/builds/limits-and-pricing/) — including memory, build minutes, and timeout remain unchanged.

src/content/docs/workers/ci-cd/builds/limits-and-pricing.mdx

@@ -13,7 +13,7 @@ Workers Builds has the following limits. While in open beta, these limits are su
 | **Build minutes**     | 3,000 per month | 6,000 per month (then, +$0.005 per minute) |
 | **Concurrent builds** | 1               | 6                                          |
 | **Build timeout**     | 20 minutes      | 20 minutes                                 |
-| **CPU**               | 2 vCPU          | 2 vCPU                                     |
+| **CPU**               | 2 vCPU          | 4 vCPU                                     |
 | **Memory**            | 8 GB            | 8 GB                                       |
 | **Disk space**        | 20 GB           | 20 GB                                      |