add percol completion plug-in

- Source: https://github.com/mooz/percol/blob/master/tools/zsh/_percol

plugins/percol/_percol

@@ -0,0 +1,16 @@
+#compdef percol
+
+local context state line
+typeset -A opt_args
+
+_arguments : \
+    '1:input file name:_files' \
+    '(--help -h)'{--help,-h}'[show this help message and exit]' \
+    '--tty=[path to the TTY]:tty:{compadd $(find /dev/pts -print)}' \
+    '--rcfile=[path to the settings file]:rc.py:_files -g \*\.py' \
+    '--encoding=[encoding for input and output]:encoding:' \
+    '--query=[pre-input query]:query:' \
+    '--match-method=[specify matching method for query.]:match method:((string\:normal\ match regex\:regular\ expression migemo\:migemo))' \
+    '--caret-position=[position of the caret]:caret position:' \
+    '--initial-index=[position of the initial index of the selection]:initial index:(first last)' \
+    '--peep[exit immediately without doing anything]'