Update lsp.md (#774)

"oin" -> "on"

Author: LazyTaz

docs/lsp.md

@@ -5,7 +5,7 @@ The goal of this library is to implement [Language Server Protocol](https://micr
 Included in this library is a full-fidelity `LanguageServer` but also full `LanguageClient` implementation that could be implemented in an editor, but mainly it is used to help make Unit Testing easier, more consistent (and maybe even fun!).
 
 # Concepts
-The language server is built oin a few concepts.  At it's core is the [MediatR](https://github.com/jbogard/MediatR) library that you will build language specific handlers around. Around that core is a bunch of knowledge of the LSP protocol
+The language server is built on a few concepts.  At it's core is the [MediatR](https://github.com/jbogard/MediatR) library that you will build language specific handlers around. Around that core is a bunch of knowledge of the LSP protocol
 with the goal of making it more ".NET" like and less protocol centric.
 
 LSP revolves around features ( eg Completion, Hover, etc ) that define the inputs (request object) the outputs (response object) as well as Client Capabilities and Server Registration Options.