docs: small semantic correction to API.md (#412)

pturley0 · web-flow · commit 0dc2f7afea17 · 2023-11-10T22:36:26.000+01:00
diff --git a/API.md b/API.md
@@ -140,7 +140,7 @@ Close the client, return immediately.
 
 `void sync_close()`
 
-Close the client, return until it is really closed.
+Close the client, don't return until it is really closed.
 
 `bool opened() const`
 
