Fix typo frragment -> fragment (#380)

<!--
Thanks for your contribution! Check out the
[contributing
docs](https://github.com/Khan/genqlient/blob/main/docs/CONTRIBUTING.md)
for more on contributing to genqlient.
-->



I have:
- [x] Written a clear PR title and description (above)
- [x] Signed the [Khan Academy CLA](https://www.khanacademy.org/r/cla)
- [X] Added tests covering my changes, if applicable
- [x] Included a link to the issue fixed, if applicable
- [x] Included documentation, for new features
- [x] Added an entry to the changelog

Author: bryanwweber

docs/CHANGELOG.md

@@ -31,6 +31,7 @@ When releasing a new version:
 
 - fixed documentation link in `introduction.md`
 - upgraded version of alexflint/go-arg from 1.4.2 to 1.5.1
+- fixed a typo in the struct + fragment error message
 
 ## v0.8.0
 

generate/genqlient_directive.go

@@ -241,7 +241,7 @@ func (dir *genqlientDirective) validate(node interface{}, schema *ast.Schema) er
 		}
 
 		if dir.Struct != nil {
-			return errorf(dir.pos, "struct is only applicable to fields, not frragment-definitions")
+			return errorf(dir.pos, "struct is only applicable to fields, not fragment-definitions")
 		}
 
 		// Like operations, anything else will just apply to the entire