Update textbook.en.md

00.brainstorming-pedagogical-teams/45.synthesis-structuring/30.classical-mechanics/05.first-steps/textbook.en.md

@@ -38,8 +38,8 @@ At this first level, chapter titles should be everyday words.
 #### To participate
 
 The different proposals are numbered: they start with : 
-[BRST-MECACLAS1-numéro] : Titre<br>
-_(BRST-MEC-CLAS1 pour Brainstorming STructure MEChanics CLASsical level 1)_
+[BRST-MECCLAS1-numéro] : Titre<br>
+_(BRST-MECCLAS1 pour Brainstorming STructure MEChanics CLASsical level 1)_
 
 To **add an item, create it** in or after existing items (following the logical order).
 To do this, start your proposition with a new : <br>
@@ -51,7 +51,7 @@ starting with three initials in brackets that represent you :
 *(my initials): my comment* 
 
 To **communicate my proposals**, either:
-* Directly on the *GitLab M3P2*:
+* Directly on the *GitLab M3P2*:<br>
 <details>
 <summary> 
 More information