nls: Update translations.

* po/doc/guix-cookbook.ru.po: New file.
* po/doc/guix-cookbook.sk.po: New file.
* po/*/*.po: Update translations.
* doc/local.mk (COOKBOOK_LANGUAGES): Add ru and sk.
(info_TEXINFOS): Add Russian and Slovak cookbooks.
* po/doc/local.mk (DOC_COOKBOOK_PO_FILES): Add Russian and Slovak po
files.

doc/local.mk

@@ -23,7 +23,7 @@
 
 # If adding a language, update the following variables, and info_TEXINFOS.
 MANUAL_LANGUAGES = de es fa fr it ko pt_BR ru sk zh_CN
-COOKBOOK_LANGUAGES = de fa fr ko zh_Hans
+COOKBOOK_LANGUAGES = de fa fr ko ru sk zh_Hans
 
 # Arg1: A list of languages codes.
 # Arg2: The file name stem.
@@ -47,6 +47,8 @@ info_TEXINFOS = %D%/guix.texi			\
   %D%/guix-cookbook.fa.texi			\
   %D%/guix-cookbook.fr.texi			\
   %D%/guix-cookbook.ko.texi			\
+  %D%/guix-cookbook.ru.texi			\
+  %D%/guix-cookbook.sk.texi			\
   %D%/guix-cookbook.zh_Hans.texi
 
 %C%_guix_TEXINFOS = \

po/doc/local.mk

@@ -34,6 +34,8 @@ DOC_COOKBOOK_PO_FILES =				\
   %D%/guix-cookbook.fa.po			\
   %D%/guix-cookbook.fr.po			\
   %D%/guix-cookbook.ko.po			\
+  %D%/guix-cookbook.ru.po			\
+  %D%/guix-cookbook.sk.po			\
   %D%/guix-cookbook.zh_Hans.po
 
 EXTRA_DIST = \