[make help] mention INITCPIO switch (#137)

This commit is an expansion to :
87b8163

Since a new `make` parameter has been introduced, it should be mentioned
in the output of the `help` target.

Also, the table is being expanded by a new column describing the type of
data that each parameter may be assigned, like paths or boolean values.

Makefile

@@ -52,11 +52,12 @@ help:
  @echo " uninstall"
  @echo " help"
  @echo
- @echo " parameters | description | defaults"
- @echo " -----------+--------------------------------+----------------------------"
- @echo " DESTDIR | install destination | <unset>"
- @echo " PREFIX | system tree prefix | '/usr'"
- @echo " SHARE_DIR | shared data location | '\$$(DESTDIR)\$$(PREFIX)/share'"
- @echo " LIB_DIR | system libraries location | '\$$(DESTDIR)\$$(PREFIX)/lib'"
- @echo " PKGNAME | name of the ditributed package | 'grub-btrfs'"
+ @echo " parameter | type | description | defaults"
+ @echo " ----------+------+--------------------------------+----------------------------"
+ @echo " DESTDIR | path | install destination | <unset>"
+ @echo " PREFIX | path | system tree prefix | '/usr'"
+ @echo " SHARE_DIR | path | shared data location | '\$$(DESTDIR)\$$(PREFIX)/share'"
+ @echo " LIB_DIR | path | system libraries location | '\$$(DESTDIR)\$$(PREFIX)/lib'"
+ @echo " PKGNAME | name | name of the ditributed package | 'grub-btrfs'"
+ @echo " INITCPIO | bool | include mkinitcpio hook | false"
  @echo