Draft: Restructuring of Data Analytics and Machine Learning sections

• create new area for Data Analytics:
  • Overview: software/data_analytics.md
  • Data Analytics with R: software/data_analytics_with_r.md
  • Data Analytics with RStudio: software/data_analytics_with_rstudio.md
  • Data Analytics with Python: software/data_analytics_with_python.md
  • Apache Spark: software/big_data_frameworks_spark.md
• create new area for Machine Learning:
  • Overview: software/machine_learning.md
  • TensorFlow: software/tensorflow.md
  • PyTorch: software/pytorch.md
  • Tensorboard: software/tensorboard.md
  • Distributed Training: software/distributed_training.md
  • Hyperparameter Optimization (OmniOpt): software/hyperparameter_optimization.md
• fuse information from the following pages into the structure above and delete these:
  • docs/software/data_analytics_with_r.md
  • docs/software/deep_learning.md
  • docs/software/get_started_with_hpcda.md
  • docs/software/keras.md,
  • docs/software/machine_learning.md
  • docs/software/python.md
  • docs/software/tensor_flow_container_on_hpcda.md
  • docs/software/tensor_flow.md
  • docs/software/tensor_flow_on_jupyter_notebook.md

Closes #157 (closed), #156 (closed), #155 (closed), #154 (closed), #153 (closed), #152 (closed), #151 (closed), #120 (closed), #119 (closed), #118 (closed), #112 (closed), #111 (closed), #110 (closed), #105 (closed), #103 (closed), #101 (closed), #99 (closed), #98 (closed)