Fix typo: fetchFromGithub -> fetchFromGitHub (#472197)

doc/languages-frameworks/nim.section.md

@@ -93,7 +93,7 @@ The `buildNimPackage` and `buildNimSbom` functions generate flags and additional
 ```nix
 pkgs.nitter.overrideNimAttrs {
   # using a different source which has different dependencies from the standard package
-  src = pkgs.fetchFromGithub {
+  src = pkgs.fetchFromGitHub {
     # …
   };
   # new lock file generated from the source

pkgs/by-name/co/commitizen-go/package.nix

@@ -8,7 +8,7 @@ buildGoModule rec {
   pname = "commitizen-go";
   version = "1.0.3";
 
-  # we can't obtain the commit hash when using fetchFromGithub
+  # we can't obtain the commit hash when using fetchFromGitHub
   commit_revision = "unspecified (nix build)";
 
   src = fetchFromGitHub {

pkgs/servers/home-assistant/custom-components/README.md

@@ -28,7 +28,7 @@ versions into the Python environment.
 buildHomeAssistantComponent {
   # owner, domain, version
 
-  src = fetchFromGithub {
+  src = fetchFromGitHub {
     # owner, repo, rev, hash
   };