fix(xfunc ARRAY filter): elaborate the option description

Author: akinomyoga

completions/ARRAY

@@ -19,17 +19,26 @@
 #   array-element value stored in the shell variable "value".
 #
 # Options:
+#
+#     The following options specify the type of the pattern.  When mutiple
+#     options are supplied, the last-specified one overwrite the previous
+#     option.
+#
 #     -E          $2 is interpreted as a POSIX extended regular expression.
 #                 The default anchoring is `-m` (see below).
 #     -F          $2 is interpreted as a fixed string.  The default anchoring
 #                 is `-m` (see below).
 #     -G          $2 is interpreted as a glob pattern.  The default anchoring
 #                 is `-x` (see below).
 #
-#     -p          Combined with -EFG, it performs the prefix matching.
-#     -s          Combined with -EFG, it performs the suffix matching.
-#     -m          Combined with -EFG, it performs the middle matching.
-#     -x          Combined with -EFG, it performs the exact matching.
+#     Combined with any of -EFG, the following options specify the anchoring
+#     type of the pattern matching.  When multiple options are supplied, the
+#     last-specified one overwrites the previous option.
+#
+#     -p          performs the prefix matching.
+#     -s          performs the suffix matching.
+#     -m          performs the middle matching.
+#     -x          performs the exact matching.
 #
 #     -r          Revert the condition, i.e., remove elements that satisfy
 #                 the original condition.