Set Up JA translation

I want to start the process for translating the User Guide to Japanese.
I've contacted the top contributor of japanese translation, and he is happy that someone start working of User Guide translation. I use git every day at work, so commit work is no problem.

This issue is to track progress on setting up for translations into Japanese.

1. [DONE] Add a new issue component for translations into this new language, by editing the Project page. The component should be called "JA translation".
2. [DONE] Make a new source/ja directory. Copy all of the source (English) files, including the images subdirectory, into the new directory. Keep the file names and IDs the same as they were in English.
3. [DONE] Add a new section to the attributions.txt file for the translation team management for this language. Template:
   

   ==== Translation into Japanese
   
   The Japanese translation of this guide was coordinated by:
   
   * https://www.drupal.org/u/person1[Person One]
   
   * https://www.drupal.org/u/person2[Person Two] of http://example.com[Company]
   

4. [DONE] Make a separate issue for the screenshots. See Guidelines document for issue template. #2885310: [JA] Japanese screenshots
5. [DONE - kabetani has permission] Grant issue maintainer and VCS commit permissions to the manager or managers of the language team for the new language, by editing the Maintainers page for the project. Note: Language team managers will need to re-clone their Git repositories using "Maintainer" mode after receiving this permission, in order to be able to commit to the repository.
6. [DONE] Make issues for translating each topic into the target language. There is a spreadsheet file scripts/bookmarks.fods that will aid in doing this.
7. [DONE] Copy the English configuration file scripts/lang-en.conf to file name lang-lc.conf, where lc is the language code. Optionally, check https://github.com/asciidoc/asciidoc to see if there is an existing language configuration file for that language, and copy the three lines we need in our language configuration file from there, so that they are translated already. [THREE LINES COPIED]
8. [DONE -- since lang-ja.conf was found, I edited the guide.txt and glossary.txt files and put in the Japanese headings for these sections] Add notes to the guide.txt and glossary.txt file translation issues, that when the chapter headers for the Preface, Index, and Glossary sections are translated, the lang-lc.conf file translations of these same words need to be done at the same time. Suggested note:
   

   When this translation is done, make sure to update the scripts/lang-lc.conf (for your language code) at the same time so the chapter headings for Preface, Index, and Glossary in that file match what is in the source file for this issue.
   

   However, if you found an existing lang-lc.conf file on Github, you should instead edit the guide.txt and glossary.txt files so that these headings match the translations you put in.

9. [DONE] Add ja to the build scripts in scripts/languages.txt, and verify that it builds without errors.
10. [DONE] At least one leader of the translation group needs to subscribe to the email list the project uses for notifications about updates to the English source that require translations to be updated. This is at:
    https://groups.google.com/forum/#!forum/d8manual
11. Optional but recommended steps:
    • [DONE] Glossary is here : https://localize.drupal.org/node/2974.
      Make a translation glossary for this language. File scripts/TermsToTranslate.fods is a good starting point. This should be located in a place that the language team normally uses for communication, such as on localize.drupal.org.
    • [DONE] https://www.drupal.org/node/2886013
      Create an issue to track translation progress. It should list the individual translation issues, providing a place to look to see which are done and which still need to be done. You can make a list of the issues in the issue summary by following these steps:
      1. Open the Issues page for the project.
      2. Filter to the issue component for your translation. You'll see the first page of issues.
      3. Open a JavaScript console tool in your browser (usually by using the Inspect or Inspect Element context menu).
      4. Execute this JavaScript code to make a list of the issue numbers shown on this page:
         

         jQuery("tbody .views-field-title a").each(
           function(){
             console.log("[#" + jQuery(this).attr("href").replace("/node/", "") + "]");
               }
         );
         

      5. Copy and paste the output into the issue summary.
      6. Go to the next page of issues and repeat the JavaScript, until all issues have been found.
12. Start translating!