ogma-cli: Re-order README's TOC to match order of contents. Refs #88.

The table of contents in the README lists C structs ahead of the ROS and FPrime
backends, but the order of in the puts those backends first.

This commit updates the TOC to reflect the current order.

ogma-cli/README.md

@@ -46,9 +46,9 @@ verification framework that generates hard real-time C99 code.
 - [Usage](#usage)
   - [Language Transformations: FRET](#language-transformations-fret)
   - [cFS Application Generation](#cfs-application-generation)
-  - [Struct Interface Generation](#struct-interface-generation)
   - [ROS Application Generation](#ros-application-generation)
   - [F' Component Generation](#f-component-generation)
+  - [Struct Interface Generation](#struct-interface-generation)
 - [Contributions](#contributions)
 - [Acknowledgements](#acknowledgements)
 - [License](#license)