Add essential_web_500k_tokens.pkl - Tokenized version (pickle format) of 500K chars from Essential-Web

Add essential_web_500k_tokens.txt - Tokenized version (one token per line) of 500K chars from Essential-Web

Add essential_web_500k_text.txt - 500K characters of raw text from Essential-Web dataset

Add tokenizer usage documentation

Upload bpe_tokenizer_16k_n1000000.pkl

initial commit