Update textbook.en.md

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

@@ -14,6 +14,12 @@ for all levels.
 
 --------------------
 
+
+! To read this page :   
+! in Spanish : https://m3p2.com/es/lessons/brainstorming-g12-classical-mechanics  
+! in French : https://m3p2.com/fr/lessons/brainstorming-g12-classical-mechanics 
+
+
 ### Foreword
 
 
@@ -50,16 +56,29 @@ starting with three initials in brackets that represent you :
 (CLM): previous comment.<br>
 *(my initials): my comment* 
 
-To **communicate my proposals**, either:<br>
-* Directly on the *GitLab M3P2*:<br>
-<details>
-<summary> More information </summary>
-Only for those who have an M3P2 account and have received the little introduction to Git:<br>
-   - Click "Améliorer ce cours" at the bottom of the page.<br>
-   - Login with your username / password
-</details>
 
-* On the *Google Docs M3P2*: to be specified.
+#### Where to contribute?
+
+To **communicate my proposals**, either :
+* directly on the GitLab m3p2 with your login/password, and after a little training on Git. 
+
+   * *Click on "Edit this course"* at the bottom of each column of this page (levels 1 and 2),   
+or of the page "https://m3p2.com/en/lessons/brainstorming-234-classical-mechanics"(levels 2, 3 and 4).
+
+   * If you prefer *to see in full screen each column* on this page, go to :   
+For these *general instructions* : https://m3p2.com/en/brainstorming-pedagogical-teams/synthesis-structuring/classical-mechanics/first-steps  
+For *level 1* : https://m3p2.com/en/brainstorming-pedagogical-teams/synthesis-structuring/classical-mechanics/n1/brainstorming
+For *level 2* : https://m3p2.com/en/brainstorming-pedagogical-teams/synthesis-structuring/classical-mechanics/n2/brainstorming  
+For *level 3* : https://m3p2.com/en/brainstorming-pedagogical-teams/synthesis-structuring/classical-mechanics/n3/brainstorming 
+For *level 4* : https://m3p2.com/en/brainstorming-pedagogical-teams/synthesis-structuring/classical-mechanics/n4/brainstorming  
+then *to contribute*, click on "*Edit this course*" at the bottom of the page. 
+
+* *In the M3P2 Googledoc* whose link has been given to you.   
+The contribution is to be made in the "Mecánica" folder, in the words documents :
+   * for *level 1* : Niv/Lev_Clas-Meca_1.docx
+   * for *level 2* : Niv/Lev_Clas-Meca_2.docx
+   * for *level 3* : Niv/Lev_Clas-Meca_3.docx
+   * for *level 4* : Niv/Lev_Clas-Meca_4.docx
 
 The Gitlab will be kept up to date with your proposals, also translated into English and Spanish.<br>
 _(This is not required, but if you can also make your contribution in French, more in_