Added Hindi Course on Maths, NLP and Flask (#11631)

* Added maths for ML

* added flask Course

* Added NLP Course

* changed alphabetical order

* Update free-courses-hi.md

* Resolve changes

* Update free-courses-hi.md

* Update free-courses-hi.md

removed invisible spaces

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Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-hi.md

@@ -596,6 +596,7 @@
 * [Discrete Mathematics (Full Course) By Dr.Gajendra Purohit](https://www.youtube.com/playlist?list=PLU6SqdYcYsfJ27O0dvuMwafS3X8CecqUg) - Gajendra Purohit
 * [Discrete Mathematics Tutorials In Hindi | B.TECH- B.E.-UGC NET- GATE- LECTURES In Hindi](https://www.youtube.com/playlist?list=PLL8qj6F8dGlTX359q-PBBUFw3BrBvAxq3) - Deepak Garg
 * [Maths for CP](https://www.youtube.com/playlist?list=PL-Jc9J83PIiFs8E0EGeckM89cD8E6sFro) - Pepcoding
+* [Maths for Machine Learning](https://www.youtube.com/playlist?list=PLKnIA16_RmvbYFaaeLY28cWeqV-3vADST) - CampusX
 * [Statistics And Probability](https://www.youtube.com/playlist?list=PLU6SqdYcYsfLRq3tu-g_hvkHDcorrtcBK) - Gajendra Purohit  
 
 
@@ -620,6 +621,7 @@
 
 ### Natural Language Processing
 
+* [Natural Language Processing](https://www.youtube.com/playlist?list=PLKnIA16_RmvZo7fp5kkIth6nRTeQQsjfX) - CampusX
 * [Natural Language Processing with Deep NLP from Zero to Hero](https://www.youtube.com/playlist?list=PLtCBuHKmdxOefxJhd6u8KY9vTN8G5D5yG) - Fahad Hussain 
 * [NLP Tutorial Playlist Python](https://www.youtube.com/playlist?list=PLeo1K3hjS3uuvuAXhYjV2lMEShq2UYSwX) - Code Basics
 * [Playlist to Natural Language Processing [ Hindi ]](https://www.youtube.com/playlist?list=PLPIwNooIb9vimsumdWeKF3BRzs9tJ-_gy) - Perfect Computer Engineer
@@ -717,6 +719,7 @@
 
 * [[Hindi] Flask Tutorial For Beginners 2020](https://www.youtube.com/playlist?list=PLkPmSWtWNIyQ-_mlHIQho9nCnxdbvnQIl) - Knowledge Shelf
 * [Flask (Python) In Hindi](https://www.youtube.com/playlist?list=PLy-CGmBdq2VGQGbhmSQEOD3Ty-Fp19pGC) - HindiSiksha
+* [Flask for Machine Learning](https://learnwith.campusx.in/courses/Flask-for-Machine-Learning-Introduction-to-Flask--Dynamic-URL-Redirection-URL-Building-Jinja-Templates-Forms--Input-Validation-Databases-Sessions-Cookies-Training--Deloyment-of-ML-Model-6658698ad54433398d1a487b) - Mohammed Misbahullah Sheriff (CampusX)
 * [Web Development Using Flask and Python](https://www.youtube.com/playlist?list=PLu0W_9lII9agAiWp6Y41ueUKx1VcTRxmf) - CodeWithHarry