Release 3.0.0

• Improve formatting support on Windows (Or add it, if it ever worked)
• Improve layout of tooltips of functions/methods. (#13)
• Improve error messages for unknown functions/methods (Related to vscode-meson#159
• Improve meson API coverage (Related to vscode-meson#159)
• Add a few missing compiler/argument/arch ids (Related to vscode-meson#159)
• Don't detect assignments from declare_dependency as unused assignments
• Improve heuristics for subdir(x) with non-constant values of x (#18)
• Add a bit of configuration possibilities, configurable with the InitializationOptions and workspace/didChangeConfiguration