removed unused files and updated README

updated: add a usage and file structure step to the readme
updated: .gitignore to prevent **result** symlink to be commited
removed: unsused file from testings

.gitignore

@@ -1 +1 @@
-result/
+result

README.md

@@ -1,3 +1,19 @@
 # linkedin_blog
 
-a collection of article posted on linkedin using markdown and presenterm
+a collection of article posted on linkedin using markdown and presenterm
+
+## File structure
+src/
+  configs/: Base configuration for presenterm
+  posts/: Posts, organized by topic
+  scripts/: Scripts used by the build process
+  Makefile: Makefile used by the build process
+
+## Usage
+### With nix
+`nix developp`: launch a shell with presenterm and weasyprint allowing the user
+to easely preview the slides in his terminal.  
+`nix build`: will build all the posts in a **result/** folder
+### With a package manager
+install `presenterm` and optionally `weasyprint` to preview and/or export each
+posts.