Fix typos (#14152)
Fix typos (#14152)

* Fix typos

This PR fixes some typos: tf.constant, tf.placeholder.

* Made tuple to real complex type.

fixed `tf.Variable((12.3, -4.85), tf.complex64)` to generate a rank
0 tensor instead of 1, the same for another error.

tensorflow/docs,tensorflow/docs,tensorflow/docs,tensorflow/docs-l10n