xtools.1, README: add xshellcheck

README

@@ -169,6 +169,12 @@ COMMANDS
      xrs pattern
         – like xbps-query -Rs, but take cwd repo into account
 
+     xshellcheck template | pkgname | :pkgname | :
+        – scan XBPS template for common shell mistakes. Requires
+        shellcheck(1).
+        - use ‘:pkgname’ to lint template as staged in the git index
+        - use ‘:’ to lint all templates staged in the git index
+
      xsrc pkg
         – list source files for XBPS template
 

xshellcheck

@@ -41,5 +41,5 @@ for argument; do
 			$XSHELLCHECK_ARGS \
 			-xa "${void_packages}/common/scripts/template_shellcheck_shim" || ret="$?"
 	fi
-done | $filter
+done
 exit $ret

xtools.1

@@ -226,6 +226,20 @@ to read templates from stdin.
 .Nd list packages shlib-dependent on package or its subpackages
 .It Nm xrs Ar pattern
 .Nd like xbps-query -Rs, but take cwd repo into account
+.It Nm xshellcheck Ar template | pkgname | Cm \&: Ns Ar pkgname | Cm \&:
+.Nd scan XBPS template for common shell mistakes.
+Requires
+.Xr shellcheck 1 .
+.Bl -dash -offset 0n -width 0n -compact
+.It
+use
+.Sq Cm \&: Ns Ar pkgname
+to lint template as staged in the git index
+.It
+use
+.Sq Cm \&:
+to lint all templates staged in the git index
+.El
 .It Nm xsrc Ar pkg
 .Nd list source files for XBPS template
 .It Nm xsubpkg \