Fix links

Signed-off-by: Jody Garnett <[email protected]>

software_development/README.md

@@ -2,13 +2,13 @@
 
 This manual is for software developers customizing or developing GeoNetwork:
 
-* [GeoNetwork Architecture Overview](overview.md) describing technologies used and application components.
+* [GeoNetwork Architecture Overview](OVERVIEW.md) describing technologies used and application components.
 * Development environment:
 
-  * [Tools](tools.md)  
+  * [Tools](TOOLS.md)  
   * [Source code](SOURCE.md)
   * [GitHub](GITHUB.md)
-  * Building
+  * [Building](BUILDING.md)
   * [Testing](TESTING.md)
   * [Eclipse IDE](ECLIPSE.md)
   * [IntelliJ IDE](INTELIJ.md).

software_development/TOOLS.md

@@ -21,22 +21,22 @@ Our source code is maintained on GitHub:
 
 ## Java 8
 
-GeoNetwork requires a Java 8 development environment.
+GeoNetwork requires a Java 8 development environment:
 
-* We recommend using the Java 8 distribution available from your operating system
+* Recommend using the Java 8 distribution available from your operating system
 * [Adopt OpenJDK8 (LTS)](https://adoptopenjdk.net/?variant=openjdk8) for windows or macOS installers
 
 We do not support development on Java 11 at this time.
 
-# Apache Maven
+## Apache Maven
 
 We make use of the Apache Maven [Apache Maven](https://maven.apache.org/) build system.
 
-Our project repository is available at repo.osgeo.org:
+Maven repository is available at repo.osgeo.org:
 
 * https://repo.osgeo.org/repository/release/
 * https://repo.osgeo.org/repository/snapshot/
 
-# Sphinx 
+## Sphinx 
 
 Documentation is built using [Sphinx](https://www.sphinx-doc.org/) python documentation generator.