Replace old docs with new docs repo (#24201)

docs/guides/install/add.mdx

@@ -0,0 +1,44 @@
+---
+title: Add a dependency
+sidebarTitle: Add a dependency
+mode: center
+---
+
+To add an npm package as a dependency, use `bun add`.
+
+```sh terminal icon="terminal"
+bun add zod
+```
+
+---
+
+This will add the package to `dependencies` in `package.json`. By default, the `^` range specifier will be used, to indicate that any future minor or patch versions are acceptable.
+
+```json package.json icon="file-json"
+{
+  "dependencies": {
+    "zod": "^3.0.0" // [!code ++]
+  }
+}
+```
+
+---
+
+To "pin" to an exact version of the package, use `--exact`. This will add the package to `dependencies` without the `^`, pinning your project to the exact version you installed.
+
+```sh terminal icon="terminal"
+bun add zod --exact
+```
+
+---
+
+To specify an exact version or a tag:
+
+```sh terminal icon="terminal"
+bun add zod@3.0.0
+bun add zod@next
+```
+
+---
+
+See [Docs > Package manager](https://bun.com/docs/cli/install) for complete documentation of Bun's package manager.