Add a draft of the specs of the files paths.

SPECIFICATIONS.md

@@ -3,6 +3,29 @@
 
 > Contributions welcome!
 
+
+## Files Paths
+
+```
+<topic>[/<topic>]/chapter<NN>-<type>.<language>.<format>
+or
+<topic>[/<topic>]/<NN>-<title>-<type>.<language>.<format>
+or
+???
+```
+
+- `topic`: lowercase alphanumeric topic name (in english, sorry)
+- `NN`: level of the course, an integer with always two digits
+- `type`: one of :
+
+  - `textbook`
+  - `cheatsheet` (?)
+  - `annex`
+
+- `language`: 2 letter lowercase language code
+- `format`: `md` for markdown
+
+
 ## Courses Model
 
 Each Course MUST have:
@@ -11,7 +34,7 @@ Each Course MUST have:
 - one Title
 - one Content
 - one Topic
-- one Language `ISO 639-1` (two letter code, eg: `fr`)
+- one Language `ISO 639-1` (two letter code, eg: `fr`) or (`ISO 3166-1 alpha-2` ? ← countries)
 
 Each course MAY have
 
@@ -20,6 +43,7 @@ Each course MAY have
 
 Keep it simple, for now.  There will be room for events (class projects, etc.) later.
 
+
 ## Course File Format
 
 We should probably follow something akin to [what Grav does](https://learn.getgrav.org/15/content/content-pages).
@@ -107,6 +131,7 @@ Directory names MUST :
 - be alphanumeric only, plus `-` and `_`.
 - validate with case-sensitivity the regex `^[a-z][a-z0-9_-]+[a-z0-9]$`
 
+
 ## Possible driver implementations
 
 - with Grav
@@ -116,10 +141,12 @@ Directory names MUST :
 
 Multiple frontends may be buit to display these courses.
 
+
 ## Tips
 
 - http://flagpedia.net/emoji
 
+
 ## TODO
 
 - Look up https://schema.org/Course and comply somehow