feat: add order of magnitude length conversion (#985)

Author: AliAlimohammadi

DIRECTORY.md

@@ -77,6 +77,7 @@
     * [Octal to Binary](https://github.com/TheAlgorithms/Rust/blob/master/src/conversions/octal_to_binary.rs)
     * [Octal to Decimal](https://github.com/TheAlgorithms/Rust/blob/master/src/conversions/octal_to_decimal.rs)
     * [Octal to Hexadecimal](https://github.com/TheAlgorithms/Rust/blob/master/src/conversions/octal_to_hexadecimal.rs)
+    * [Order of Magnitude Conversion](https://github.com/TheAlgorithms/Rust/blob/master/src/conversions/order_of_magnitude_conversion.rs)
     * [RGB-CMYK Conversion](https://github.com/TheAlgorithms/Rust/blob/master/src/conversions/rgb_cmyk_conversion.rs)
   * Data Structures
     * [AVL Tree](https://github.com/TheAlgorithms/Rust/blob/master/src/data_structures/avl_tree.rs)

src/conversions/mod.rs

@@ -11,7 +11,9 @@ mod length_conversion;
 mod octal_to_binary;
 mod octal_to_decimal;
 mod octal_to_hexadecimal;
+mod order_of_magnitude_conversion;
 mod rgb_cmyk_conversion;
+
 pub use self::binary_to_decimal::binary_to_decimal;
 pub use self::binary_to_hexadecimal::binary_to_hexadecimal;
 pub use self::binary_to_octal::binary_to_octal;
@@ -25,4 +27,7 @@ pub use self::length_conversion::length_conversion;
 pub use self::octal_to_binary::octal_to_binary;
 pub use self::octal_to_decimal::octal_to_decimal;
 pub use self::octal_to_hexadecimal::octal_to_hexadecimal;
+pub use self::order_of_magnitude_conversion::{
+    convert_metric_length, metric_length_conversion, MetricLengthUnit,
+};
 pub use self::rgb_cmyk_conversion::rgb_to_cmyk;