Breaking: shell hook defaults

Fish is not the default shell anymore. For traditional
shells, users now need to call:

```sh
eval "$(dirp hook)"
```

Fish users should use:

```fish
dirp hook fish | source
```

Previously, users would call `dirp hook bash`. Now
the shell hook is compatible with BusyBox and a few
other variants, so the default has been changed.

main.go

@@ -25,10 +25,10 @@ func main() {
 			cfg := dirp.FindDirs(arg0)
 			dirp.Selector(cfg)
 		} else if arg0 == "hook" {
-			if len(args) >= 2 && args[1] == "bash" {
-				dirp.PrintBashHook()
+			if len(args) >= 2 && args[1] == "fish" {
+				dirp.PrintFishHook()
 			} else {
-				dirp.PrintHook() // fish
+				dirp.PrintHook()
 			}
 		} else if arg0 == "cfg" {
 			fmt.Print(dirp.GetConfigPath())

src/hook.go

@@ -2,8 +2,8 @@ package dirp
 
 import "fmt"
 
-// PrintBashHook emits shell code for Bash, ZSH, sh, BusyBox, etc
-func PrintBashHook() {
+// PrintHook emits shell code for Bash, ZSH, sh, BusyBox, etc
+func PrintHook() {
 	// 1) Remove existing "dir" aliases, if any exit
 	// 2) Detect and prefer pushd over cd
 	// 3) Provide "dir" function
@@ -34,8 +34,8 @@ function dir() {
 	export -f dir &> /dev/null`)
 }
 
-// PrintHook emits shell code for Fish
-func PrintHook() {
+// PrintFishHook emits shell code for Fish
+func PrintFishHook() {
 	fmt.Println(`function dir
 		set stdout (dirp $argv)
 		if [ $status = 2 ]