Revert "doc: import() is supported now"

This reverts commit 977fb13.

This should not have landed on v9.x which does not yet
support the feature

Author: MylesBorins

doc/api/esm.md

@@ -33,14 +33,15 @@ node --experimental-modules my-app.mjs
 ### Supported
 
 Only the CLI argument for the main entry point to the program can be an entry
-point into an ESM graph. Dynamic import can also be used with the flag
-`--harmony-dynamic-import` to create entry points into ESM graphs at run time.
+point into an ESM graph. In the future `import()` can be used to create entry
+points into ESM graphs at run time.
 
 ### Unsupported
 
 | Feature | Reason |
 | --- | --- |
-| `require('./foo.mjs')` | ES Modules have differing resolution and timing, use dynamic import |
+| `require('./foo.mjs')` | ES Modules have differing resolution and timing, use language standard `import()` |
+| `import()` | pending newer V8 release used in Node.js |
 | `import.meta` | pending V8 implementation |
 
 ## Notable differences between `import` and `require`