Add demo test variant

We're piggybacking on our existing integration test framework to record  demos that we can include in our docs

pkg/integration/tests/demo/commit_and_push.go

@@ -0,0 +1,56 @@
+package demo
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var CommitAndPush = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Make a commit and push",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	IsDemo:       true,
+	SetupConfig: func(config *config.AppConfig) {
+		// No idea why I had to use version 2: it should be using my own computer's
+		// font and the one iterm uses is version 3.
+		config.UserConfig.Gui.NerdFontsVersion = "2"
+	},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFile("my-file.txt", "myfile content")
+		shell.CreateFile("my-other-file.rb", "my-other-file content")
+
+		shell.CreateNCommitsWithRandomMessages(30)
+		shell.NewBranch("feature/demo")
+
+		shell.CloneIntoRemote("origin")
+
+		shell.SetBranchUpstream("feature/demo", "origin/feature/demo")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.SetCaptionPrefix("Stage a file")
+
+		t.Views().Files().
+			IsFocused().
+			PressPrimaryAction().
+			SetCaptionPrefix("Commit our changes").
+			Press(keys.Files.CommitChanges)
+
+		t.ExpectPopup().CommitMessagePanel().
+			Type("my commit summary").
+			SwitchToDescription().
+			Type("my commit description").
+			SwitchToSummary().
+			Confirm()
+
+		t.Views().Commits().
+			TopLines(
+				Contains("my commit summary"),
+			)
+
+		t.SetCaptionPrefix("Push to the remote")
+
+		t.Views().Files().
+			IsFocused().
+			Press(keys.Universal.Push)
+	},
+})