support autocd option

In bash, when autocd option is set and user enters a directory name as a
command, it results in a very specific call to cd:

cd -- [directory name]

zoxide's directory changing function passes all arguments to __zoxide_z as is,
including the "--" first argument. By detecting this and skipping the first
argument changing directory works with autocd set.

templates/bash.txt

@@ -102,7 +102,13 @@ function __zoxide_zi() {
 
 \builtin unalias {{cmd}} &>/dev/null || \builtin true
 function {{cmd}}() {
-    __zoxide_z "$@"
+    if [[ $# -eq 2 && "$1" == "--" && -d $2 ]]; then
+        # This is how cd is called when bash's autocd option is set. To get the
+        # directory-changing behavior first argument must be skipped.
+        __zoxide_z "${@:2}"
+    else
+        __zoxide_z "$@"
+    fi
 }
 
 \builtin unalias {{cmd}}i &>/dev/null || \builtin true