Fix broken link to quickstart in the README (#1207)

# why
Link points to the old docs route

# what changed
Fixed link to the
[Quickstart](https://docs.stagehand.dev/v3/first-steps/quickstart)
section of the docs on the readme
Shoutout to @JerryWu1234 for the contrib

# test plan

---------

Co-authored-by: Jerry_wu <[email protected]>

Author: miguelg719

.changeset/brave-mangos-reply.md

@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+Fix broken links to quickstart docs

README.md

@@ -65,7 +65,7 @@ Most existing browser automation tools either require you to write low-level cod
 
 ## Getting Started
 
-Start with Stagehand with one line of code, or check out our [Quickstart Guide](https://docs.stagehand.dev/get_started/quickstart) for more information:
+Start with Stagehand with one line of code, or check out our [Quickstart Guide](https://docs.stagehand.dev/v3/first-steps/quickstart) for more information:
 
 ```bash
 npx create-browser-app

packages/core/README.md

@@ -65,7 +65,7 @@ Most existing browser automation tools either require you to write low-level cod
 
 ## Getting Started
 
-Start with Stagehand with one line of code, or check out our [Quickstart Guide](https://docs.stagehand.dev/get_started/quickstart) for more information:
+Start with Stagehand with one line of code, or check out our [Quickstart Guide](https://docs.stagehand.dev/v3/first-steps/quickstart) for more information:
 
 ```bash
 npx create-browser-app