Add optional 4040 aluminum profile base mount (#113)

* Create README.md for 4040_Base_Mount

* Add images for 4040_base_mount

* Update README.md for 4040_base_mount

* Upload stl/ and step/ for 4040_base_mount

* Add 4040 base mount in addons

Renamed section from "Raised Leader Base" to "Mounting Bases"
Added new entry for 4040 aluminum profile mount

Optional/4040_Base_Mount/README.md

@@ -0,0 +1,25 @@
+## Base Mount for 4040 Aluminum Profiles
+
+<p align="left">
+  <img src="../../media/4040_base_mount.jpg" width="300" />
+  <img src="../../media/4040_base_mount_side.jpg" width="300" />
+</p>
+
+This 3D-printed adapter allows you to securely attach your **SO-100 base** to standard **40×40 mm aluminum extrusion profiles** (8.2 mm slot width).  
+Perfect for building a sturdy, modular platform for your robotic arm.
+
+- 📦 [Download STL](./stl/4040_base_mount.stl)  
+- 📐 [Download STEP](./step/4040_base_mount.step)
+
+### 🛠 Assembly Instructions
+
+- Use **1 × M4×16 mm bolt** and **1 × M4 T-nut (8 mm slot)** to attach the adapter to the aluminum profile.  
+- Use **4 × M4×30 mm bolts** and **4 × M4 wing nuts** to secure the **SO-100 base** to the mount.  
+> The holes are 5 mm in diameter, so M5 hardware can also be used.
+
+### 🖨 Suggested Print Orientation
+
+For optimal strength, print the part in the orientation shown below.  
+> Supports are required.
+
+<img src="../../media/4040_base_mount_print_orientation.png" width="600" />

README.md

@@ -197,12 +197,12 @@ For bird’s‑eye views in single or bi‑manual setups.
 <img src="https://github.com/user-attachments/assets/a652e133-8672-448d-baa0-bdd494a0a515" height="200"> | <img src="media/overhead_cam_two_followers.png" height="200"> 
 | [Instructions](Optional/Overhead_Cam_Mount_Webcam/README.md) | [Instructions](Optional/Overhead_Cam_Mount_32x32_UVC_Module/README.md) 
 
-#### 3. Raised Leader Base  
-Lift your leader arm for low‑ground tasks.
+#### 3. Base Mounts
 
-[→ Download STL](Optional/Raised_Base/Raised_Base_Extension.stl)
-
-<img src="media/Raised_Base.jpeg" alt="Raised Leader Base" width="150">
+| Raised Leader Base | 4040 Aluminum Profile Mount |
+|:-------------------:|:---------------------------:|
+<img src="media/Raised_Base.jpeg" height="150"> | <img src="media/4040_base_mount.jpg" height="150">  
+[Download STL](Optional/Raised_Base/Raised_Base_Extension.stl) | [Instructions](Optional/4040_Base_Mount/README.md)
 
 #### 4. Tactile Sensing (AnySkin)  
 Add touch sensing to your gripper.