Update README.md

1. Changed version from 1.1.0 to version 1.2.0.

2. Updated documentation.
3. New functions added to cargo.toml (contract, compatible_stdapi, support_size_check_transmute).
4. Updated examples.
5. Completely changed the file hierarchy, broken compatibility with version 1.1.0 and younger.

1. Updated examples, updated documentation, updated readme

2. Library version changed to 1.1
3. Added some const signs of functions
4. Permanent removal of obsolete modules and functions

1. Minor fixes, preparation for release.

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Update README.md

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