Fix typo (bitfield#186)

Author: jessp01

README.md

@@ -313,7 +313,7 @@ Filters are methods on an existing pipe that also return a pipe, allowing you to
 | [`SHA256Sums`](https://pkg.go.dev/github.com/bitfield/script#Pipe.SHA256Sums) | SHA-256 hashes of each listed file |
 | [`Tee`](https://pkg.go.dev/github.com/bitfield/script#Pipe.Tee) | input copied to supplied writers |
 
-Note that filters run concurrently, rather than producing nothing until each stage has fully read its input. This is convenient for executing long-running comands, for example. If you do need to wait for the pipeline to complete, call [`Wait`](https://pkg.go.dev/github.com/bitfield/script#Pipe.Wait).
+Note that filters run concurrently, rather than producing nothing until each stage has fully read its input. This is convenient for executing long-running commands, for example. If you do need to wait for the pipeline to complete, call [`Wait`](https://pkg.go.dev/github.com/bitfield/script#Pipe.Wait).
 
 ## Sinks