Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,4 +1,35 @@
-To get started, [please sign the Contributor License Agreement](https://www.clahub.com/agreements/wekan/wekan).
+## Contributing to wiki
 
-[Then, please read documentation at wiki](https://github.com/wekan/wekan/wiki).
+Please clone wiki:
+```
+git clone https://github.com/wekan/wekan.wiki
+```
+Edit .md files, and add changed files in .zip attachment
+directly to comment of new issue at
+https://github.com/wekan/wekan/issues 
 
+## Contributing code
+
+[Building WeKan and sending PR](https://github.com/wekan/wekan/wiki/Emoji).
+
+Also see other docs at wiki.
+
+Do not use code formattung or linting like eslist
+or prettier.
+
+WeKan code has MIT license.
+
+## Contributing translations
+
+Non-English translations are contributed only at
+https://transifex.com/wekan/wekan
+
+When adding new features, in your PR to
+https://github.com/wekan/wekan/pulls
+only add new English source language strings
+to https://github.com/wekan/wekan/blob/master/imports/i18n/data/en.i18n.json
+
+Maintainer of WeKan xet7 downloads all newest
+translations from Transifex and adds
+them to WeKan repo before making
+new release.