feat(refacto): move everything in internal package

This allows to install katenary with `go install` and to clean up the
project folder.

internal/generator/doc.go

@@ -0,0 +1,17 @@
+/*
+Package generator generates kubernetes objects from a "compose" file and transforms them into a helm chart.
+
+The generator package is the core of katenary. It is responsible for generating kubernetes objects from a compose file
+and transforming them into a helm chart.
+Conversion manipulates Yaml representation of kubernetes object to add conditions, labels, annotations, etc. to the
+objects. It also create the values to be set to the values.yaml file.
+
+The generate.Convert() create an HelmChart object and call "Generate()" method to convert from a compose file to a helm
+chart. It saves the helm chart in the given directory.
+
+If you want to change or override the write behavior, you can use the HelmChart.Generate() function and implement your
+own write function. This function returns
+the helm chart object containing all kubernetes objects and helm chart ingormation. It does not write the helm chart to
+the disk.
+*/
+package generator