Fix typo in README test steps (#4541)

Co-authored-by: Casey Gardiner <117784577+ONECasey@users.noreply.github.com>
Co-authored-by: Max <82761650+MaxMustermann2@users.noreply.github.com>
Co-authored-by: Soph <35721420+sophoah@users.noreply.github.com>
Co-authored-by: Konstantin <355847+Frozen@users.noreply.github.com>
Co-authored-by: Nita Neou (Soph) <soph@harmony.one>
Co-authored-by: Diego Nava <diego.nava77@hotmail.com>
Co-authored-by: Diego Nava <8563843+diego1q2w@users.noreply.github.com>
Co-authored-by: Gheis Mohammadi <Gheis.Mohammadi@gmail.com>
Co-authored-by: “GheisMohammadi” <36589218+GheisMohammadi@users.noreply.github.com>
Co-authored-by: Adam Androulidakis <37982984+adsorptionenthalpy@users.noreply.github.com>

README.md

@@ -150,7 +150,7 @@ make debug-kill
 
 To keep things consistent, we have a docker image to run all tests. **These are the same tests ran on the pull request checks**.
 
-Note that all testing docker container binds a couple of ports to the host machine for your convince. The ports are:
+Note that all test Docker containers bind several ports to the host machine for your convenience. The ports are:
 * `9500` - Shard 0 RPC for a validator
 * `9501` - Shard 1 RPC for a validator
 * `9599` - Shard 0 RPC for an explorer