docs: polish

Author: brillout

docs/pages/globalContext/+Page.mdx

@@ -190,9 +190,8 @@ declare global {
   }
 }
 
-// If you define Vike.GlobalContext in a .d.ts file then
-// make sure there is at least one export/import statement.
-// Tell TypeScript this file isn't an ambient module:
+// Add this line if TypeScript complains about `declare global`.
+// https://typescriptlang.org/docs/handbook/2/modules.html#how-javascript-modules-are-defined
 export {}
 ```
 

docs/pages/meta/+Page.mdx

@@ -563,9 +563,8 @@ declare global {
   }
 }
 
-// The following isn't needed in this example, but if you define Vike.Config
-// in a .d.ts file then make sure there is at least one export/import statement.
-// Tell TypeScript this file isn't an ambient module:
+// Add this line if TypeScript complains about `declare global`.
+// https://typescriptlang.org/docs/handbook/2/modules.html#how-javascript-modules-are-defined
 export {}
 ```
 

docs/pages/pageContext/+Page.mdx

@@ -570,9 +570,8 @@ declare global {
   }
 }
 
-// If you define Vike.PageContext in a .d.ts file then
-// make sure there is at least one export/import statement.
-// Tell TypeScript this file isn't an ambient module:
+// Add this line if TypeScript complains about `declare global`.
+// https://typescriptlang.org/docs/handbook/2/modules.html#how-javascript-modules-are-defined
 export {}
 ```