ssh/config: there is an Include directive since openssh 7.8

.install.conf.yaml

@@ -10,7 +10,6 @@
     ~/.bash_profile: bash/profile
     ~/.gitconfig: git/gitconfig
     ~/.gitignore_global: git/gitignore_global
-    ~/.config/geany/geany.conf: geany/geany.conf
     ~/.config/geany/keybindings.conf: geany/keybindings.conf
     ~/.config/geany/filedefs: geany/filedefs
     ~/.ncmpcpp/config: ncmpcpp/config

ssh/config

@@ -0,0 +1,11 @@
+# Include separate configs from ~/.ssh/config.d/
+Include ~/.ssh/config.d/*
+
+# Github
+Host github.com
+User git
+
+# Defaults
+Host *
+IdentitiesOnly yes
+IdentityFile ~/.ssh/%h