You can use various markdown-previewer programs to see this documentation offline. Once you download No-CMS, you can find this documentation located at /doc/tutorial.md
.
If you use chrome browser, you can install an extension named Markdown Preview. Once you install the extension, go to chrome://extensions and activate Allow access to file urls
. Open up the documentation by using google chrome, and enjoy.
If you use firefox, you can install an addons named Markdown Viewer
You can also use github's atom text editor.