docs: fix typo

Author: gearcog

README.md

@@ -103,7 +103,7 @@ The `copilot.panel` module exposes the following functions:
 require("copilot.panel").accept()
 require("copilot.panel").jump_next()
 require("copilot.panel").jump_prev()
-require("copilot.panel").open({postion, ratio})
+require("copilot.panel").open({position, ratio})
 require("copilot.panel").refresh()
 ```