Added details to index.md

Author: siddhi-244

Index.md

@@ -52,3 +52,4 @@
 | [Image Filter App]()                                                                                                            |An Awesome Image Filter App written in Html,Css,Javascript and CamanJS.|
 | [Form Validation](https://github.com/Ayushparikh-code/Web-dev-mini-projects/tree/main/form-validation)                         |A basic sign up page with all the validations in javascript.   |     
 | [Age Calculator](https://github.com/Ayushparikh-code/Web-dev-mini-projects/tree/main/age-calculator)                           | A website which can be used to calculate age of a person in days,months and years . |
+| [BMI Calculator](https://github.com/Ayushparikh-code/Web-dev-mini-projects/tree/main/bmi-calculator)                           | A basic website which can be used to calculate body mass index |