added usage and setup instructions

README.md

@@ -1,9 +1,20 @@
 #Page Meta-Data
 
-A plugin to add meta-data for each generated page in the format:
+A Pelican plugin to add meta-data for each generated page in the format:
 
 `index.html Tue 12 Nov 2019 03:52:15 PM CET 57.637KB`
 
 It calculates the weight of the HTML page including all image media. A time stamp reflecting the date of generation is also added.
 
 The data is appended at the end of the HTML, so nothing fancy for now.
+
+## Usage and setup
+
+To use this plugin first import `strftime` at the top of `pelican.conf`:
+
+`from time import strftime`
+
+Then add `NOW = strftime('%c')` somewhere in that document as well. This saves the time of generation as a variable that is usable by the `page_metadata` plugin. 
+
+To enable the plugin add it to the `PLUGINS` list in `pelicanconf.py`.
+