docs(concepts) correct main fileds title in the text to make sense (#3329)

Author: EugeneHlushko

src/content/concepts/module-resolution.md

@@ -66,7 +66,7 @@ Once the path is resolved based on the above rule, the resolver checks to see if
 If the path points to a folder, then the following steps are taken to find the right file with the right extension:
 
 - If the folder contains a `package.json` file, then fields specified in [`resolve.mainFields`](/configuration/resolve/#resolvemainfields) configuration option are looked up in order, and the first such field in `package.json` determines the file path.
-- If there is no `package.json` or if the main fields do not return a valid path, file names specified in the [`resolve.mainFiles`](/configuration/resolve/#resolvemainfiles) configuration option are looked for in order, to see if a matching filename exists in the imported/required directory .
+- If there is no `package.json` or if the [`resolve.mainFields`](/configuration/resolve/#resolvemainfields) do not return a valid path, file names specified in the [`resolve.mainFiles`](/configuration/resolve/#resolvemainfiles) configuration option are looked for in order, to see if a matching filename exists in the imported/required directory .
 - The file extension is then resolved in a similar way using the [`resolve.extensions`](/configuration/resolve/#resolveextensions) option.
 
 webpack provides reasonable [defaults](/configuration/resolve) for these options depending on your build target.