Preprocessing includes building the InputSpace, checking the input dimensions and assigning the inputs to parameters.

Finished the example for BayesInf for the user guide and fixed some small bugs for MCMC with a single input.
Started working on the user guide for BMC, but issue in AL with changes in the model

A first draft of the contribution guidelines can now be found in `CONTRIBUTING.md`.
The website was rebuilt, but does not include the guidelines yet.

User guide startet for models, surrogate training, sequential training, postprocessing and BAyesian classes. The guide now contains simplified UMLs (for BayesInf not yet done).

Webpage includes quickstart, user guide, tutorial, example collection and api.
One new example was added for the user guide.

Build api pages with autosummary and modified templates to include class documentation.
Tutorial updated to BVR 1.0.0 (engine use).

Copied the first version of the sphinx documentation into the docs/source folder. It can be built in html format with '.\make html'.
This includes start of API documentation, summaries of the examples and a tutorial for the 'analytical function' example for BVR version 0.0.5.

An example 'principal_component_analysis' was added to specifically test this functionality. It uses the analytical model.
Fixed two if-calls in `pca_transformation` to match older code and the content of the function.