removing old-playgrounds (PR from TinaCMS) (#2318)

TinaCMS content update

Co-authored-by: tina-cloud-app[bot] <58178390+tina-cloud-app[bot]@users.noreply.github.com>

content/docs/schema.mdx

@@ -80,8 +80,6 @@ fields: [
 ]
 ```
 
-[Live Example...](https://tina-gql-playground.vercel.app/string-list)
-
 ### Caveats
 
 Certain field types cannot be set as a list, or may not have a specific list UI when changed through the content editor. To create lists of these fields, they can [be wrapped](/docs/reference/types/object/#using-list-object-as-a-wrapper-for-other-types) in an object field type that has been been marked with `list: true`.
@@ -123,8 +121,6 @@ fields: [
 ]
 ```
 
-[See Example](https://tina-gql-playground.vercel.app/string-list-options)
-
 > Omitting `list: true` (or setting it to `false`) would result in a single-select `radio` field.
 
 ## Grouping properties as an "object"
@@ -163,11 +159,7 @@ fields: [
 // ...
 ```
 
-[See Example](https://tina-gql-playground.vercel.app/object)
-
-Setting `list: true` would turn the values into an array:
-
-[See Example](https://tina-gql-playground.vercel.app/object-list-data)
+Setting `list: true` would turn the values into an array.
 
 > More complex shapes can be built by using the [`templates`](/docs/reference/types/object/#with-multiple-templates) property. This allows your editors to build out pages using predefined blocks.
 
@@ -209,7 +201,7 @@ export default defineConfig({
 
 ### Default value for objects
 
-To set default values for objects of fields, use the `defaultItem` property (see [example here](https://tina-gql-playground.vercel.app/object-list-data)).
+To set default values for objects of fields, use the `defaultItem` property.
 
 ### Default value for rich-text
 
@@ -281,8 +273,6 @@ fields: [
 //
 ```
 
-[See Example](https://tina-gql-playground.vercel.app/reference)
-
 ## Available data types
 
 Each field in a collection can be of the following `type`: