Add huffman solutions for C and Rust

Author: yannvanhalewyn

Solutions/challenge-huffman.md

@@ -35,4 +35,6 @@ The shared solutions:
 | 27 | [KCompressor](https://github.com/kiner-shah/MySolutionsToCodingChallenges/tree/main/compression-tool) | C++ | [Kiner Shah](https://github.com/kiner-shah) |
 | 28 | [zippy](https://github.com/ravil-gasanov/zippy) | Python | [Ravil Gasanov](https://github.com/ravil-gasanov) |
 | 29 | [huffman-compressor-cpp](https://github.com/r-harsh-r/huffman-encoder-cpp-optimised) | C++ | [Harsh R](https://github.com/r-harsh-r) |
-| 30 | [challenge-huffman](https://github.com/blissful-coder/CodingChallenges/tree/main/challenge-huffman) | C++ | [Anurag Negi](https://github.com/blissful-coder) |
+| 30 | [challenge-huffman](https://github.com/blissful-coder/CodingChallenges/tree/main/challenge-huffman) | C++ | [Anurag Negi](https://github.com/blissful-coder) |
+| 31 | [huffman-encoder-c](https://github.com/yannvanhalewyn/coding-challenges/tree/main/huffman-encoder-c) | C | [Yann Vanhalewyn](https://github.com/yannvanhalewyn) |
+| 32 | [huffman-encoder-rust](https://github.com/yannvanhalewyn/coding-challenges/tree/main/huffman-encoder-rust) | Rust | [Yann Vanhalewyn](https://github.com/yannvanhalewyn) |