Documentation/move build documentation to repository

[nmarquesin]

Description:

Move build documentation from GitHub's Wiki to appropriate folder inside the repository.

Related issue:

Is related but does not close issue #170.

Motivation and Context:

This change brings the necessary information to build the TotalCross VM on a different platform to the corresponding platform folder inside the repository. Previously it would be necessary to access the Wiki to read the build documentation. This was done for iOS, Android and Linux as it was already done for Windows.

Benefited Devices:

• OS: iOS, Android and Linux

How Has This Been Tested?

• The documentations was copied as is from the Wiki with no alterations.

[teras]

I agree with the idea of putting the required build information inside the source code itself for these reasons:

• Wiki is part of the underlying infrastructure, which makes it difficult to maintain and relocate
• The source code is not self-contained, i.e. when I download the repository this information is lost
• It's more difficult to accept PRs for updates of the documentation

[teras]

The commit message should be updated in order for the PR to be accepted.