Document default values in cookies options (vercel#72183)

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### What?

Document the default values for `cookies`, eg. used in
`cookies().set()`, fix typo

### Why?

Default values are undocumented (probably because there are almost no
default values)

![Screenshot 2024-11-01 at 16 20
57](https://github.com/user-attachments/assets/7de705f0-f0db-491d-9582-6f65f9688730)


### How?

1. Add a default annotation in the options table row for `path`, based
on the `packages/next/src/compiled/@edge-runtime/cookies/index.js` code:

https://github.com/vercel/next.js/blob/98fa0246d9d6f6adfcac91d8d9997672390cd051/packages/next/src/compiled/%40edge-runtime/cookies/index.js#L317-L328
2. Add a short paragraph about other options not having default values
3. Fix the extra `,` typo

---------

Co-authored-by: JJ Kasper <jj@jjsweb.site>

docs/02-app/02-api-reference/04-functions/cookies.mdx

@@ -52,14 +52,16 @@ When setting a cookie, the following properties from the `options` object are su
 | `expires`         | Date                                   | Defines the exact date when the cookie will expire.                                |
 | `maxAge`          | Number                                 | Sets the cookie’s lifespan in seconds.                                             |
 | `domain`          | String                                 | Specifies the domain where the cookie is available.                                |
-| `path`            | String                                 | Limits the cookie's scope to a specific path within the domain.                    |
-| `secure`          | Boolean,                               | Ensures the cookie is sent only over HTTPS connections for added security.         |
+| `path`            | String, default: `'/'`                 | Limits the cookie's scope to a specific path within the domain.                    |
+| `secure`          | Boolean                                | Ensures the cookie is sent only over HTTPS connections for added security.         |
 | `httpOnly`        | Boolean                                | Restricts the cookie to HTTP requests, preventing client-side access.              |
 | `sameSite`        | Boolean, `'lax'`, `'strict'`, `'none'` | Controls the cookie's cross-site request behavior.                                 |
 | `priority`        | String (`"low"`, `"medium"`, `"high"`) | Specifies the cookie's priority                                                    |
 | `encode('value')` | Function                               | Specifies a function that will be used to encode a cookie's value.                 |
 | `partitioned`     | Boolean                                | Indicates whether the cookie is [partitioned](https://github.com/privacycg/CHIPS). |
 
+The only option with a default value is `path`.
+
 To learn more about these options, see the [MDN docs](https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies).
 
 ## Good to know