Delete redundant examples from user gallery that are also present in the annotations tutorial (matplotlib#25153)

* added redirects in annotations.py header and deleted redundant annotate_* examples in
gallery/userdemo

Author: erg0dic

examples/userdemo/anchored_box04.py

@@ -1,4 +1,12 @@
 r"""
+.. redirect-from:: /gallery/userdemo/annotate_simple01
+.. redirect-from:: /gallery/userdemo/annotate_simple02
+.. redirect-from:: /gallery/userdemo/annotate_simple03
+.. redirect-from:: /gallery/userdemo/annotate_simple04
+.. redirect-from:: /gallery/userdemo/anchored_box04
+.. redirect-from:: /gallery/userdemo/annotate_simple_coord01
+.. redirect-from:: /gallery/userdemo/annotate_simple_coord03
+
 Annotations
 ===========
 
@@ -170,6 +178,7 @@
 #
 # Placing text annotations relative to data
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+#
 # Annotations can be positioned at a relative offset to the *xy* input to
 # annotation by setting the *textcoords* keyword argument to ``'offset points'``
 # or ``'offset pixels'``.