feat: add main.c, change ci.yml

.gitea/workflows/ci.yml

@@ -1,9 +1,10 @@
-ame: First CI
+name: First CI
 on: [push]
 
 jobs:
   build:
   runs-on: ubuntu-latest
   steps:
-      - name: Printing hello
-        run: echo "Hello world!"
+    - uses: actions/checkout@v4
+    - name: build using gcc
+      run: gcc -Wall -Werror main.c

main.c

@@ -0,0 +1,5 @@
+int main()
+{
+    printf("Halo, Welt!");
+    return 0;
+}