Add suggestion "strategy" concept with default strategy

src/strategies/default.zsh

@@ -0,0 +1,17 @@
+
+#--------------------------------------------------------------------#
+# Default Suggestion Strategy                                        #
+#--------------------------------------------------------------------#
+# Suggests the most recent history item that matches the given
+# prefix.
+#
+
+_zsh_autosuggest_strategy_default() {
+	local prefix="$(_zsh_autosuggest_escape_command_prefix "$1")"
+
+	# Get the hist number of the most recent history item that matches
+	local histkey="${${(k)history[(R)$prefix*]}[1]}"
+
+	# Echo the history entry
+	echo -E "${history[$histkey]}"
+}