Clarify image formats and size in media plugin and forms (#42)

## 📜 Details
- Explicitly state devvit supports data URLs and WEBPs.
- Add supported formats and size limit to the image field in forms 

## 🧪 Testing Steps / Validation
Tested with `yarn start`

**Image docs:**
<img width="915" height="247" alt="Screenshot 2026-02-03 at 4 35 13 PM"
src="https://github.com/user-attachments/assets/a7a69279-bd52-454a-b151-19883acd9866"
/>

**Forms docs:**
<img width="915" height="164" alt="Screenshot 2026-02-03 at 4 36 03 PM"
src="https://github.com/user-attachments/assets/6cbd9a29-0750-4609-bea7-8b4afc54c154"
/>



## ✅ Checks
<!-- Make sure your pr passes the CI checks and do check the following
fields as needed - -->
- [ ] CI tests (if present) are passing
- [ ] Adheres to code style for repo
- [ ] Contributor License Agreement (CLA) completed if not a Reddit
employee

---------

Co-authored-by: Caio Araujo <[email protected]>

Author: kay0tickay

docs/capabilities/client/forms.mdx

@@ -511,6 +511,12 @@ const imageField = {
 | `placeholder` | `string` `undefined`                                                           | Placeholder text for display before a value is present.                                                                                                          |
 | `isSecret`    | `boolean` `undefined`                                                          | Makes the form field secret.                                                                                                                                     |
 
+#### Notes
+
+- The formats supported are PNG, JPEG, WEBP, and GIF.
+- The maximum file size allowed is 20 MB.
+- When uploading a WEBP image, it will be converted to JPEG. As such, the Reddit URL returned points to a JPEG image.
+
 ### Group
 
 A collection of related fields that allows for better readability.

docs/capabilities/server/media-uploads.mdx

@@ -22,7 +22,7 @@ Enable the `media` permission in your `devvit.json` file.
 ```
 
 ## Using media uploads
-On the server, you can pass the URL of any remotely hosted image (even if its not hosted on Reddit) to the `media.upload` function. The media function will return a Reddit URL.
+On the server, you can pass the URL of any remotely hosted image (even if its not hosted on Reddit) to the `media.upload` function. This function will return a Reddit URL. Both HTTP and data URLs are supported.
 
 <Tabs>
   <TabItem value="web" label="Devvit Web">
@@ -50,9 +50,10 @@ On the server, you can pass the URL of any remotely hosted image (even if its no
 
 
 ## Limitations
-Supported file types are:
-- GIF
-- PNG
-- JPEG
 
-Maximum size is 20 MB.
+- The formats supported are PNG, JPEG, WEBP, and GIF.
+- The maximum file size allowed is 20 MB.
+
+### Notes
+
+- When uploading a WEBP image, it will be converted to JPEG. As such, the Reddit URL returned points to a JPEG image.

versioned_docs/version-0.12/capabilities/client/forms.mdx

@@ -511,6 +511,12 @@ const imageField = {
 | `placeholder` | `string` `undefined`                                                           | Placeholder text for display before a value is present.                                                                                                          |
 | `isSecret`    | `boolean` `undefined`                                                          | Makes the form field secret.                                                                                                                                     |
 
+#### Notes
+
+- The formats supported are PNG, JPEG, WEBP, and GIF.
+- The maximum file size allowed is 20 MB.
+- When uploading a WEBP image, it will be converted to JPEG. As such, the Reddit URL returned points to a JPEG image.
+
 ### Group
 
 A collection of related fields that allows for better readability.

versioned_docs/version-0.12/capabilities/server/media-uploads.mdx

@@ -22,7 +22,7 @@ Enable the `media` permission in your `devvit.json` file.
 ```
 
 ## Using media uploads
-On the server, you can pass the URL of any remotely hosted image (even if its not hosted on Reddit) to the `media.upload` function. The media function will return a Reddit URL.
+On the server, you can pass the URL of any remotely hosted image (even if its not hosted on Reddit) to the `media.upload` function. This function will return a Reddit URL. Both HTTP and data URLs are supported.
 
 <Tabs>
   <TabItem value="web" label="Devvit Web">
@@ -50,9 +50,10 @@ On the server, you can pass the URL of any remotely hosted image (even if its no
 
 
 ## Limitations
-Supported file types are:
-- GIF
-- PNG
-- JPEG
 
-Maximum size is 20 MB.
+- The formats supported are PNG, JPEG, WEBP, and GIF.
+- The maximum file size allowed is 20 MB.
+
+### Notes
+
+- When uploading a WEBP image, it will be converted to JPEG. As such, the Reddit URL returned points to a JPEG image.