Add author of "Build Web Application with Golang" (#10405)

* Add author of "Build Web Application with Golang"

* remove github beside author

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

---------

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

books/free-programming-books-langs.md

@@ -810,7 +810,7 @@ Books on general-purpose programming that don't focus on a specific language are
 ### Go
 
 * [An Introduction to Programming in Go](https://www.golang-book.com/books/intro) - Caleb Doxsey
-* [Build Web Application with Golang](https://astaxie.gitbooks.io/build-web-application-with-golang/content/en/)
+* [Build Web Application with Golang](https://astaxie.gitbooks.io/build-web-application-with-golang/content/en/) - astaxie
 * [Building Web Apps with Go](https://codegangsta.gitbooks.io/building-web-apps-with-go/content/)
 * [Darker Corners of Go](https://rytisbiel.com/2021/03/06/darker-corners-of-go/) - Rytis Bieliunas
 * [Effective Go](https://golang.org/doc/effective_go.html)