Fix minimal typo in diff-tool.order.md (#607)

Author: bitbonk

docs/diff-tool.order.md

@@ -39,7 +39,7 @@ To change this file edit the source file and then run MarkdownSnippets.
 
 ### ViaEnvironment Variable
 
-Set an `DiffEngine_ToolOrder` environment variable with the preferred order of toll resolution. The value can be comma (`,`), pipe (`|`), or space separated.
+Set an `DiffEngine_ToolOrder` environment variable with the preferred order of tool resolution. The value can be comma (`,`), pipe (`|`), or space separated.
 
 For example `VisualStudio,Meld` will result in VisualStudio then Meld then all other tools being the order.