Moved comment tokens from Tokens.java to Comments.java

Separate tokens into Tokens.java, Keywords.java and Operators.java

Added package-info.java

Changed method signatures

Optimized some codes in Tokenizer#execute

Optimized some codes in Tokenizer#splitBySpace

Changed the way to split tokens by symbols and fixed known bugs.

Removed some regex constants.

Use String#length instead of String#codePointCount

Updated test declarations.

Tokenizer#splitBySymbol is still buggy.

Added test case for Tokenizer#splitBySpace and Tokenizer#splitBySymbol

Added test case for Tokenizer#splitBySymbol

Changed access modifiers to be able to access methods in Tokenizer.java from TokenizerTest.java

Added test case for Tokenizer#splitBySymbol.

Implemented Tokenizer#splitBySymbols to be able to tokenize by more symbols.

Implemented equals() to test in JUnit 5.

Implemented new constructor and fixed toString() and JavaDoc comments.

Added maven-surefire-plugin to see test reports in browsers.

Added Position#move method.

Renamed some fields and methods in Token.java.

Made simple test-case for tokenizer.

Implemented model-file tokenizer that has abilities to tokenize comments and splits token by spaces.

Made skeleton of a model-file validator.

Implemented LSP4J to be able to launch basic language server.

Updated Parser.java to be able to read model file with multiline comments.

Updated model file for testing

Updated Parser.java to be able to read model file with single-line comments.

Changed model file for testing.

Created Test case for comment feature.