Merge pull request #3771 from kaingwade:refine_ml_doc

Correct some links in the tutorials #3771

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

Author: kaingwade

modules/ml/tutorials/cpp_ml/introduction_to_svm/introduction_to_svm.markdown

@@ -105,23 +105,23 @@ Source Code
 
 @add_toggle_cpp
 -   **Downloadable code**: Click
-    [here](https://github.com/opencv/opencv/tree/5.x/samples/cpp/tutorial_code/ml/introduction_to_svm/introduction_to_svm.cpp)
+    [here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples/introduction_to_svm.cpp)
 
 -   **Code at glance:**
     @include samples/introduction_to_svm.cpp
 @end_toggle
 
 @add_toggle_java
 -   **Downloadable code**: Click
-    [here](https://github.com/opencv/opencv/tree/5.x/samples/java/tutorial_code/ml/introduction_to_svm/IntroductionToSVMDemo.java)
+    [here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples/java/tutorial_code/ml/introduction_to_svm/IntroductionToSVMDemo.java)
 
 -   **Code at glance:**
     @include samples/java/tutorial_code/ml/introduction_to_svm/IntroductionToSVMDemo.java
 @end_toggle
 
 @add_toggle_python
 -   **Downloadable code**: Click
-    [here](https://github.com/opencv/opencv/tree/5.x/samples/python/tutorial_code/ml/introduction_to_svm/introduction_to_svm.py)
+    [here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples/python/tutorial_code/ml/introduction_to_svm/introduction_to_svm.py)
 
 -   **Code at glance:**
     @include samples/python/tutorial_code/ml/introduction_to_svm/introduction_to_svm.py

modules/ml/tutorials/cpp_ml/non_linear_svms/non_linear_svms.markdown

@@ -95,8 +95,8 @@ account these rules:
 Source Code
 -----------
 
-You may also find the source code in `samples/cpp/tutorial_code/ml/non_linear_svms` folder of the OpenCV source library or
-[download it from here](https://github.com/opencv/opencv/tree/5.x/samples/cpp/tutorial_code/ml/non_linear_svms/non_linear_svms.cpp).
+You may also find the source code in `ml/samples` folder of the OpenCV source library or
+[download it from here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples).
 
 @add_toggle_cpp
 -   **Downloadable code**: Click
@@ -108,15 +108,15 @@ You may also find the source code in `samples/cpp/tutorial_code/ml/non_linear_sv
 
 @add_toggle_java
 -   **Downloadable code**: Click
-    [here](https://github.com/opencv/opencv/tree/5.x/samples/java/tutorial_code/ml/non_linear_svms/NonLinearSVMsDemo.java)
+    [here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples/java/tutorial_code/ml/non_linear_svms/NonLinearSVMsDemo.java)
 
 -   **Code at glance:**
     @include samples/java/tutorial_code/ml/non_linear_svms/NonLinearSVMsDemo.java
 @end_toggle
 
 @add_toggle_python
 -   **Downloadable code**: Click
-    [here](https://github.com/opencv/opencv/tree/5.x/samples/python/tutorial_code/ml/non_linear_svms/non_linear_svms.py)
+    [here](https://github.com/opencv/opencv_contrib/tree/5.x/modules/ml/samples/python/tutorial_code/ml/non_linear_svms/non_linear_svms.py)
 
 -   **Code at glance:**
     @include samples/python/tutorial_code/ml/non_linear_svms/non_linear_svms.py