Fixed non ssl links

Author: Umesh Yadav

README.md

@@ -82,9 +82,9 @@ repeat these steps to upgrade to future releases.
 ## Building
 
 * [FreeBSD](./docs/build-instructions/freebsd.md)
-* [Linux](http://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-linux)
-* [macOS](http://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-mac)
-* [Windows](http://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-windows)
+* [Linux](https://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-linux)
+* [macOS](https://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-mac)
+* [Windows](https://flight-manual.atom.io/hacking-atom/sections/hacking-on-atom-core/#platform-windows)
 
 ## License