[elm] Documenting/exemplifying the following:

[elm] Documenting/exemplifying the following:
 - elm_gengrid_add
 - elm_gengrid_align_get
 - elm_gengrid_align_set
 - elm_gengrid_always_select_mode_get
 - elm_gengrid_always_select_mode_set
 - elm_gengrid_bounce_get
 - elm_gengrid_bounce_set
 - elm_gengrid_clear
 - elm_gengrid_horizontal_get
 - elm_gengrid_horizontal_set
 - elm_gengrid_multi_select_get
 - elm_gengrid_multi_select_set
 - elm_gengrid_no_select_mode_get
 - elm_gengrid_no_select_mode_set
 - elm_gengrid_page_relative_get
 - elm_gengrid_page_relative_set
 - elm_gengrid_page_size_set

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/elementary@61704 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33