snippets: fix the inc front matter

- Fixes the front matter for the incremental notes files, removing
  unnecessary metadata and adding the id.

Co-Authored-by: iGor milhit <igor@milhit.ch>

my_snippets/markdown.lua

@@ -112,9 +112,8 @@ return {
       [[
         ---
         title: {1}
-        creation_date: {2}
+        date: {2}
-        author: iGor milhit
+        id: {4}
-        categories: [inc]
         tags: [notes, quotidien, {3}]
         ---
 
@@ -122,7 +121,8 @@ return {
       {
         f(get_month_year, {}),
         f(get_datetime, {}),
-        f(get_month, {})
+        f(get_month, {}),
+        f(get_id, {})
       }
     )
   ),

spell/en.utf-8.add

@@ -9,3 +9,4 @@ Réaménagement
 biodiversité
 hyperindustrialisés
 lacto-fermentation
+d'engrain