make site localizable using po4a

* fsfe#29
* fsfe/reuse-docs#61

README.md

@@ -55,6 +55,12 @@ The website "chrome" strings are localized using the standard,
 built-in [Hugo i18n](https://gohugo.io/content-management/multilingual/)
 support.  Those files are in _data/_.
 
+Translation happens by conversion Markdown into _gettext_ using
+[po4a](https://po4a.org).  To generate the _.md_ files from the
+_gettext .po_ files, run: `po4a po/po4a.conf`.  This also regenerates
+the _.pot_ file, which is the _gettext_ translation template, and
+syncs changes to the _.po_ files.
+
 ## License
 
 The theme used for this website is based on [github-project-landing-page](https://github.com/nsomar/github-project-landing-page) which is licensed under the

site/po/po4a.conf

@@ -0,0 +1,11 @@
+[po4a_langs] es
+[po4a_paths] po/reuse-website.pot $lang:po/reuse-website.$lang.po
+
+[options] opt:"--addendum-charset=UTF-8" opt:"--localized-charset=UTF-8" opt:"--master-charset=UTF-8" opt:"--master-language=en_US" opt:"--msgmerge-opt='--no-wrap'" opt:"--porefs=file" opt:"--wrap-po=newlines"
+
+[po4a_alias:markdown] text opt:"--option markdown" opt:"--option yfm_keys=title" opt:"--addendum-charset=UTF-8" opt:"--localized-charset=UTF-8" opt:"--master-charset=UTF-8" opt:"--keep=100"
+
+
+[type: markdown] content/comparison.md $lang:$lang/content/comparison.md
+[type: markdown] content/dev.md $lang:$lang/content/dev.md
+[type: markdown] content/materials.md $lang:$lang/content/materials.md