doc: spec_apis.md  basePath, relativePath (#1096)

Update spec to say that basePath and relativePath must NOT start with `/`

Fixes: https://github.com/apache/openwhisk-wskdeploy/issues/1095
diff --git a/specification/html/spec_apis.md b/specification/html/spec_apis.md
index b26d02c..df59fa7 100644
--- a/specification/html/spec_apis.md
+++ b/specification/html/spec_apis.md
@@ -99,8 +99,8 @@
 ### Requirements
 
 - The API name MUST be less than or equal to 256 characters.
-- The API `basePath` value MUST start with a `/` character.
-- The APi `relativePath` value MUST start with a `/` character.
+- The API `basePath` value MUST NOT start with a `/` character.
+- The API `relativePath` value MUST NOT start with a `/` character.
 - The API entity schema includes all required fields declared above.
 - Only web actions, actions having `web-export` set to `true`, can be used as an API endpoint's action.
     - If needed, the action will be automatically converted to a web action during deployment.