diff --git a/dev.README.md b/dev.README.md
index 8561869..a3a8d33 100644
--- a/dev.README.md
+++ b/dev.README.md
@@ -1,4 +1,56 @@
 
+# Developer Notes
+
+
+1. add pdm in pipx
+```sh
+pipx install --suffix "@gsheet-tools" pdm --python python3.12
+```
+
+2. prepare pdm
+- as we already have `pdm.lock` file
+```sh
+pdm@gsheet-tools sync
+```
+
+
+## Bulding this package with pdm
+
+- [Video Tute 1](https://www.youtube.com/watch?v=qOIWNSTYfcc)
+    
+    KeyPoints
+    -   explained briefly - why we need **pipx**
+    -   initializing a new project with pdm
+    -   concept of groups in pdm
+    -   customizing .vscode settings.json for pdm
+
+    > little outdated .
+
+    > recommended watch speed : 1.25x
+
+.
+
+- [Video Tute 2](https://www.youtube.com/watch?v=cOFyf0_CDhI)
+    
+    KeyPoints
+    -   explained why to choose *pdm* over *poetry*
+    -   explained in detail - why we need **pipx**
+    -   initializing a new project with pdm
+    -   dependency installation not explained in much detail
+    
+    > latest and fresh .
+
+    > recommended watch speed : 1.25x
+
+.
+
+- [Video Tute 3](https://www.youtube.com/watch?v=wh8RUrg6f6o&t=399s)
+
+    KeyPoints
+    - 
+    -   concept of groups in pdm
+    -   dependency installation explained in detail
+    -   doesn't use pipx , nor explains about it .
 
 ## Nox
 
diff --git a/developer.md b/developer.md
deleted file mode 100644
index 0c201ee..0000000
--- a/developer.md
+++ /dev/null
@@ -1,52 +0,0 @@
-# Developer Notes
-
-
-1. add pdm in pipx
-```sh
-pipx install --suffix "@gsheet-tools" pdm --python python3.12
-```
-
-2. prepare pdm
-- as we already have `pdm.lock` file
-```sh
-pdm@gsheet-tools sync
-```
-
-
-## Bulding this package with pdm
-
-- [Video Tute 1](https://www.youtube.com/watch?v=qOIWNSTYfcc)
-    
-    KeyPoints
-    -   explained briefly - why we need **pipx**
-    -   initializing a new project with pdm
-    -   concept of groups in pdm
-    -   customizing .vscode settings.json for pdm
-
-    > little outdated .
-
-    > recommended watch speed : 1.25x
-
-.
-
-- [Video Tute 2](https://www.youtube.com/watch?v=cOFyf0_CDhI)
-    
-    KeyPoints
-    -   explained why to choose *pdm* over *poetry*
-    -   explained in detail - why we need **pipx**
-    -   initializing a new project with pdm
-    -   dependency installation not explained in much detail
-    
-    > latest and fresh .
-
-    > recommended watch speed : 1.25x
-
-.
-
-- [Video Tute 3](https://www.youtube.com/watch?v=wh8RUrg6f6o&t=399s)
-
-    KeyPoints
-    - 
-    -   concept of groups in pdm
-    -   dependency installation explained in detail
-    -   doesn't use pipx , nor explains about it .
\ No newline at end of file