Add Gemfile and build instructions

Author: az0

Gemfile

@@ -0,0 +1,10 @@
+source "https://rubygems.org"
+
+#https://talk.jekyllrb.com/t/liquid-4-0-3-tainted/7946/12
+
+gem 'liquid', '>= 4.0', '< 6.0'
+gem 'jekyll', '>= 4.3.2'
+gem 'jekyll-redirect-from'
+
+
+

README.md

@@ -1,12 +1,25 @@
 # BleachBit Documentation
 
-[Read the documentation.](https://docs.bleachbit.org/)
+Are you a user wanting to learn how to use BleachBit? [Read the documentation.](https://docs.bleachbit.org/)
 
-Help improve this documentation:
+# Build
+
+```sh
+sudo apt-get update
+sudo apt-get install gnupg2 ruby jekyll bundle
+sudo apt-get remove ruby-liquid # in case installed earlier
+bundle install
+bundle exec jekyll serve
+bundle exec jekyll build
+```
+
+# Help improve
 
 1. Log in to GitHub.
 2. Fork this repository to make your own copy.
 3. Make the edits in your own repository.
 4. Submit a pull request to merge your changes.
 
+# License
+
 The documentation is under the GNU General Public License version 3 or later