README.md: Add missing word

The word `sha1s' is MIA.  Add it.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 4746865..2f0b4f9 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ When Git is asked to perform a network operation with a URL that starts with e.g
 In GitTorrent's case, we could be asked for three styles of URL:
 * `gittorrent://some.git.hosting.site/somerepo` -- we connect over `git://` to find out what the latest commit is, then perform the download using that commit's sha1.  This is kind of like a [CDN](CDN) for a git server; the actual download of objects happens via peers, but the lookup of which objects to downloads happens in the normal Git way.
 * `gittorrent://<hex sha1>/reponame` -- the sha1 corresponds to a gittorrent user's "mutable key" (hash of their public key) on our DHT -- we look up the key, receive JSON describing the user's repositories, and then perform the download using that commit's sha1.  This doesn't use any resources outside of GitTorrent's network.
-* `gittorrent://<username>` -- the username is converted into a mutable key sha1 as above.  The mapping from usernames to  happens on Bitcoin's blockchain in OP_RETURN transaction.
+* `gittorrent://<username>` -- the username is converted into a mutable key sha1 as above.  The mapping from usernames to sha1s happens on Bitcoin's blockchain in OP_RETURN transaction.
 
 ## 2. Distributed hash table