Tidy up ExampleUsageTest.floatMatrixExampleUsageTest() and add it to the GH wiki

[JonasSchaub]

[Mila1004]

@JonasSchaub I revised the comments. Please have a look at them so I can revise the Wiki pages.

[JonasSchaub]

@Mila1004 done, see pull request 👍

[Mila1004]

@JonasSchaub added overhauled example usage wiki page, please take a look and comment on possible changes/additions.

[JonasSchaub]

@Mila1004 I have adjusted the wiki page directly and sent a PR to your branch with corresponding changes in the test code.

[Mila1004]

@JonasSchaub The new page is an overhauled version of the chapters 1.-3., which makes them obsolete. Additionally, their content is outdated. With your permission, the chapters can be removed and exchanged with the new page.

[JonasSchaub]

Sure, go ahead 👍

[Mila1004]

removed the outdated wiki entries