Fix links of bootstrap under HTML (#2487)

free-programming-books.md

@@ -1252,8 +1252,8 @@
 
 #### Bootstrap
 
-* [Twitter Bootstrap 3 Succinctly](https://www.syncfusion.com/resources/techportal/ebooks/twitterbootstrap3) (PDF, Kindle) *(Just fill the fields with any values)*
-* [Twitter Bootstrap Succinctly](https://www.syncfusion.com/resources/techportal/ebooks/twitterbootstrap) (PDF, Kindle) *(Just fill the fields with any values)*
+* [Twitter Bootstrap 3 Succinctly](https://www.syncfusion.com/resources/techportal/details/ebooks/twitterbootstrap3) (PDF, Kindle) *(Just fill the fields with any values)*
+* [Twitter Bootstrap Succinctly](https://www.syncfusion.com/resources/techportal/details/ebooks/twitterbootstrap) (PDF, Kindle) *(Just fill the fields with any values)*
 
 
 #### HTTP