Fix typos in comments detected by the misspell tool

Author: TysonAndre

README.md

@@ -86,7 +86,7 @@ Definitions resolved just-in-time when needed:
 Not supported yet:
  - constants with `define()`
 
-Namespaces are not considerd a declaration by design because they only make up a part of the fully qualified name
+Namespaces are not considered a declaration by design because they only make up a part of the fully qualified name
 and don't map to one unique declaration.
 
 ### What is considered a reference?

src/DefinitionResolver.php

@@ -1091,7 +1091,7 @@ public function getTypeFromNode($node)
 
             $parameterDocBlockTag = $this->tryGetDocBlockTagForParameter($docBlock, $variableName);
             if ($parameterDocBlockTag !== null && ($type = $parameterDocBlockTag->getType())) {
-                // Doc block comments supercede all other forms of type inference
+                // Doc block comments supersede all other forms of type inference
                 return $type;
             }
 

src/Indexer.php

@@ -96,7 +96,7 @@ public function __construct(
     }
 
     /**
-     * Will read and parse the passed source files in the project and add them to the appropiate indexes
+     * Will read and parse the passed source files in the project and add them to the appropriate indexes
      *
      * @return Promise <void>
      */