Add help text for zsh/bash completion

README.md

@@ -98,7 +98,7 @@ Requirements:
 # Installation
 
 1. Copy the executable (from the [releases page][releases]) to somewhere in your path, named `dstask` and mark it executable. `/usr/local/bin/` is suggested.
-1. Enable bash completions by copying `.bash-completion.sh` into your home directory and sourcing it from your `.bashrc`. There's also a zsh completion script.
+1. Enable bash completions by copying `source <(dstask bash-completion)` into your `.bashrc`. There's also a `zsh-completion` subcommand.
 1. Set up an alias in your `.bashrc`: `alias task=dstask` or `alias t=dstask` to make task management slightly faster.
 1. Create or clone a ~/.dstask git repository for the data, if you haven't already: `mkdir ~/.dstask && git -C ~/.dstask init`.
 
@@ -162,6 +162,8 @@ show-open         : Show all non-resolved tasks (without truncation)
 show-resolved     : Show resolved tasks
 show-templates    : Show task templates
 show-unorganised  : Show untagged tasks with no projects (global context)
+bash-completion   : Print bash completion script to stdout
+zsh-completion    : Print zsh completion script to stdout
 help              : Get help on any command or show this message
 version           : Show dstask version information
 ```

completions/embed.go

@@ -3,8 +3,10 @@ package completions
 //nolint
 import _ "embed"
 
+// Zsh completion script
 //go:embed zsh.sh
 var Zsh string
 
+// Bash completion script
 //go:embed bash.sh
 var Bash string

help.go

@@ -209,6 +209,15 @@ this command.
 		helpStr = `Usage: dstask show-projects
 
 Show a breakdown of projects with progress information
+`
+
+	case CMD_PRINT_BASH_COMPLETION, CMD_PRINT_ZSH_COMPLETION:
+		helpStr = `Usage: dstask [bash|zsh]-completion
+
+Print a shell completion script to stdout. The script can be sourced from
+a user's .bashrc or .zshrc like so:
+
+    source <(dstask bash-completion)
 `
 	default:
 		helpStr = `Usage: dstask [id...] <cmd> [task summary/filter]
@@ -253,12 +262,14 @@ show-open         : Show all non-resolved tasks (without truncation)
 show-resolved     : Show resolved tasks
 show-templates    : Show task templates
 show-unorganised  : Show untagged tasks with no projects (global context)
+bash-completion   : Print bash completion script to stdout
+zsh-completion    : Print zsh completion script to stdout
 help              : Get help on any command or show this message
 version           : Show dstask version information
 
 Colour Key:
-
 `
+
 		showKey = true
 	}
 	fmt.Fprint(os.Stderr, helpStr)