ref(nix): drop neovim legacy support

nix/home/common/neovim/nvim/snippets/c.json

@@ -0,0 +1,27 @@
+{
+	"Create main function": {
+		"prefix": "main",
+		"body": [
+			"int main()",
+			"{",
+			"\t$0",
+			"\treturn 0;",
+			"}"
+		]
+	},
+	"Debug expression": {
+		"prefix": "dbg",
+		"body": [
+			"printf(\"${1:expression}: ${2:format}\\n\", ${1:expression});"
+		]
+	},
+	"Check pointer": {
+		"prefix": "cpt",
+		"body": [
+			"if (${1:ptr} == NULL) {",
+			"\treturn $2;",
+			"}",
+			"$0"
+		]
+	}
+}