docs: codemode upgrade command (#87006)

Author: icyJoseph

docs/01-app/02-guides/upgrading/codemods.mdx

@@ -22,6 +22,43 @@ Replacing `<transform>` and `<path>` with appropriate values.
 - `--dry` Do a dry-run, no code will be edited
 - `--print` Prints the changed output for comparison
 
+## Upgrade
+
+Upgrades your Next.js application, automatically running codemods and updating Next.js, React, and React DOM.
+
+```bash filename="Terminal"
+npx @next/codemod upgrade [revision]
+```
+
+### Options
+
+- `revision` (optional): Specify the upgrade type (`patch`, `minor`, `major`), an NPM dist tag (e.g. `latest`, `canary`, `rc`), or an exact version (e.g. `15.0.0`). Defaults to `minor` for stable versions.
+- `--verbose`: Show more detailed output during the upgrade process.
+
+For example:
+
+```bash filename="Terminal"
+# Upgrade to the latest patch (e.g. 16.0.7 -> 16.0.8)
+npx @next/codemod upgrade patch
+
+# Upgrade to the latest minor (e.g. 15.3.7 -> 15.4.8). This is the default.
+npx @next/codemod upgrade minor
+
+# Upgrade to the latest major (e.g. 15.5.7 -> 16.0.7)
+npx @next/codemod upgrade major
+
+# Upgrade to a specific version
+npx @next/codemod upgrade 16
+
+# Upgrade to the canary release
+npx @next/codemod upgrade canary
+```
+
+> **Good to know**:
+>
+> - If the target version is the same as or lower than your current version, the command exits without making changes.
+> - During the upgrade, you may be prompted to choose which Next.js codemods to apply and run React 19 codemods if upgrading React.
+
 ## Codemods
 
 ### 16.0

docs/01-app/03-api-reference/06-cli/next.mdx

@@ -187,7 +187,7 @@ To ensure `next-env.d.ts` is present before type-checking run `next typegen`. Th
 
 > **Good to know**: `next typegen` loads your Next.js config (`next.config.js`, `next.config.mjs`, or `next.config.ts`) using the production build phase. Ensure any required environment variables and dependencies are available so the config can load correctly.
 
-## `next upgrade` options
+### `next upgrade` options
 
 `next upgrade` upgrades your Next.js application to the latest version.