docs: Document CLI performance optimization setup (#787)

Co-authored-by: promptless[bot] <179508745+promptless[bot]@users.noreply.github.com>
Co-authored-by: Devin Logan <[email protected]>

Author: promptless[bot]

fern/products/cli-api-reference/pages/cli-get-started.mdx

@@ -13,7 +13,50 @@ npm install -g fern-api # install Fern CLI
 fern -v # ensure Fern was successfully installed
 ```
 
-## CLI Quick Start
+<Accordion title="Installing Fern CLI locally" toc={true}>
+
+If you're experiencing network delays with the global installation, working in an environment with limited internet connectivity, or prefer to manage Fern as a project dependency, you can install the CLI locally:
+
+<Steps>
+<Step title="Install as project dependency">
+
+Add `fern-api` to your project dependencies:
+
+```bash
+npm install fern-api
+```
+
+</Step>
+
+<Step title="Update configuration">
+
+In your `fern.config.json`, set the version to `*` to use your locally installed version:
+
+```json fern.config.json {3}
+{
+  "organization": "your-org",
+  "version": "*"
+}
+```
+
+</Step>
+
+<Step title="Run via package manager">
+
+Use your package manager to run Fern commands:
+
+```bash
+npm fern check        # Validate API definition
+npm fern --version    # Check CLI version
+npm fern generate     # Generate outputs
+```
+
+</Step>
+</Steps>
+
+</Accordion>
+
+## CLI quickstart
 
 Get started with these commonly used commands:
 
@@ -36,7 +79,7 @@ fern generate --group ts-sdk     # Generate specific SDK group
 The "default SDK group" refers to the group marked as default in your `generators.yml`. Learn more about [default groups](/learn/sdks/introduction/configuration).
 </Note>
 
-## Common Workflows
+## Common workflows
 
 <AccordionGroup>
   <Accordion title="Setting up Docs">