Update README.md - spacing

Co-authored-by: Jose Storopoli <[email protected]>

Author: pazzo83

README.md

@@ -55,7 +55,7 @@ tfidf_mat = transform(mach, ngram_docs)
 ```
 
 ## BM25 Transformer
-BM25 is an approach similar to that of TF-IDF in terms of representing documents in a vector space.  The BM25 scoring function uses both term frequency (TF) and inverse document frequency (IDF) so that, for each term in a document, its relative concentration in the document is scored (like TF-IDF).  However, BM25 improves upon TF-IDF by incorporating probability - particularly, the probability that a user will consider a search result relevant based on the terms in the search query and those in each document.
+BM25 is an approach similar to that of TF-IDF in terms of representing documents in a vector space. The BM25 scoring function uses both term frequency (TF) and inverse document frequency (IDF) so that, for each term in a document, its relative concentration in the document is scored (like TF-IDF). However, BM25 improves upon TF-IDF by incorporating probability - particularly, the probability that a user will consider a search result relevant based on the terms in the search query and those in each document.
 
 ### Usage
 This transformer is used in much the same way as the `TfidfTransformer`.