Provide basic project documentation

[nesterone]

• provide project's README
• define propose of the project, alternatives
• define how to contribute to the project
• define the architecture/structure of the project, how to write a test (unit tests/ integration tests)
• define license

[0pdd]

@nesterone 7 puzzles #89, #90, #91, #92, #93, #94, #95 are still not solved.

[0pdd]

@nesterone 8 puzzles #89, #90, #91, #92, #93, #94, #95, #97 are still not solved.

[0pdd]

@nesterone 7 puzzles #91, #92, #93, #94, #95, #97, #99 are still not solved; solved: #89, #90.

[0pdd]

@nesterone 6 puzzles #91, #92, #93, #94, #95, #97 are still not solved; solved: #89, #90, #99.

[0pdd]

@nesterone 5 puzzles #91, #92, #93, #94, #95 are still not solved; solved: #89, #90, #97, #99.

[0pdd]

@nesterone 4 puzzles #92, #93, #94, #95 are still not solved; solved: #89, #90, #91, #97, #99.

[nesterone]

actually basic docs done, however contributing issues not documented yet

[0pdd]

@nesterone 4 puzzles #unknown, #unknown, #unknown, #unknown are still not solved.