Revert "Add Decodal formatter"

This reverts commit 22f6bc1ab9.

crates/decodal-core/src/lib.rs

@@ -7,7 +7,6 @@ pub mod constraints;
 pub mod diagnostic;
 pub mod embedding;
 pub mod eval;
-pub mod formatter;
 mod lexer;
 pub mod module;
 pub mod parser;
@@ -22,7 +21,6 @@ pub use decodal_derive::Decodal;
 pub use diagnostic::{Diagnostic, DiagnosticKind, Result};
 pub use embedding::{HostField, HostValue};
 pub use eval::{Engine, format_diagnostic_with};
-pub use formatter::{format_source, format_source_with_source_id};
 pub use module::{EmptyLoader, LoadedSource, Module, SourceLoader};
 pub use parser::{ParseOutput, Parser, SourceForm, parse_source, parse_source_with_source_id};
 pub use runtime::{Constraint, Data, ExprRef, LiteralValue, ModuleId, PrimitiveType, RuntimeValue};