Added wording provided by Alan Bateman in CSR discussion: 'The reader…

… is initially opened and reading starts at the first character in the sequence.'

src/java.base/share/classes/java/io/Reader.java

@@ -144,7 +144,8 @@ public void close() {
      * Returns a {@code Reader} that reads characters from a
      * {@code CharSequence}.
      *
-     * Reading starts at the first character in the sequence.
+     * The reader is initially opened and reading starts at the
+     * first character in the sequence.
      *
      * <p> The resulting reader is not safe for use by multiple
      * concurrent threads. If the reader is to be used by more than one