fix type of SchemaProperties.document.text (#35245)

according to docs at https://docs.slatejs.org/slate-core/schema#text
can be either a RegExp or a function taking a string
and returning a boolean

types/slate/index.d.ts

@@ -49,7 +49,7 @@ export interface Rules {
     }>;
     normalize?: (editor: Editor, error: SlateError) => void;
     parent?: ObjectAndType | ObjectAndType[];
-    text?: RegExp;
+    text?: RegExp | ((text: string) => boolean);
 }
 
 export interface SchemaProperties {

types/slate/slate-tests.ts

@@ -74,7 +74,8 @@ const schema: SchemaProperties = {
                 }
             }
         },
-        marks: [{ type: 'bold' }, { type: t => ['bold', 'underline'].indexOf(t) !== -1 }]
+        marks: [{ type: 'bold' }, { type: t => ['bold', 'underline'].indexOf(t) !== -1 }],
+        text: /^Test$/
     },
     blocks: {
         image: {
@@ -84,6 +85,14 @@ const schema: SchemaProperties = {
     },
 };
 
+const schema2: SchemaProperties = {
+    document: {
+        text(text) {
+            return true;
+        }
+    }
+};
+
 const pluginCommandName = 'plugin_command';
 const pluginQueryName = 'plugin_query';