<iconv.h>: clarify the docs a bit more.

Bug: https://github.com/android/ndk/issues/1895
Test: N/A
Change-Id: I68542e3b4d98ec5ae0e0ed1d199c2b4b23e98f6d
diff --git a/libc/include/iconv.h b/libc/include/iconv.h
index 794a292..27e04bb 100644
--- a/libc/include/iconv.h
+++ b/libc/include/iconv.h
@@ -50,6 +50,12 @@
  * [iconv_open(3)](http://man7.org/linux/man-pages/man3/iconv_open.3.html) allocates a new converter
  * from `__src_encoding` to `__dst_encoding`.
  *
+ * Android supports the `utf8`, `ascii`, `usascii`, `utf16be`, `utf16le`, `utf32be`, `utf32le`,
+ * and `wchart` encodings for both source and destination.
+ *
+ * Android supports the GNU `//IGNORE` and `//TRANSLIT` extensions for the
+ * destination encoding.
+ *
  * Returns a new `iconv_t` on success and returns `((iconv_t) -1)` and sets `errno` on failure.
  *
  * Available since API level 28.
@@ -60,9 +66,6 @@
  * [iconv(3)](http://man7.org/linux/man-pages/man3/iconv.3.html) converts characters from one
  * encoding to another.
  *
- * Android supports the `utf8`, `ascii`, `usascii`, `utf16be`, `utf16le`, `utf32be`, `utf32le`,
- * and `wchart` encodings. Android also supports the GNU `//IGNORE` and `//TRANSLIT` extensions.
- *
  * Returns the number of characters converted on success and returns `((size_t) -1)` and
  * sets `errno` on failure.
  *