Fixed binary name in description output

Added missing "s" character in description output.

Signed-off-by: @lb1a <github@lb1a.de>
Signed-off-by: Brittan DeYoung <32572259+brittandeyoung@users.noreply.github.com>

cmd/completion/completion.go

@@ -38,17 +38,17 @@ func NewCommand() *cobra.Command {
 const longDescription = `Outputs terraform-doc shell completion for the given shell (bash, zsh, fish)
 This depends on the bash-completion binary.  Example installation instructions:
 # for bash users
-	$ terraform-doc completion bash > ~/.terraform-doc-completion
+	$ terraform-docs completion bash > ~/.terraform-doc-completion
 	$ source ~/.terraform-doc-completion
 
 # for zsh users
-	% terraform-doc completion zsh > /usr/local/share/zsh/site-functions/_terraform-doc
+	% terraform-docs completion zsh > /usr/local/share/zsh/site-functions/_terraform-doc
 	% autoload -U compinit && compinit
 # or if zsh-completion is installed via homebrew
-    % terraform-doc completion zsh > "${fpath[1]}/_terraform-doc"
+    % terraform-docs completion zsh > "${fpath[1]}/_terraform-doc"
 
 # for fish users
-	$ terraform-doc completion fish > ~/.config/fish/completions/terraform-docs.fish
+	$ terraform-docs completion fish > ~/.config/fish/completions/terraform-docs.fish
 
 Additionally, you may want to output the completion to a file and source in your .bashrc
 Note for zsh users: [1] zsh completions are only supported in versions of zsh >= 5.2