Feat: Adds More Information to Summary Panel (#100)

This MR adds more information into the summary view, including the MR author, created at date, merge status, draft status, conflicts, and pipeline status, among other things. This is configurable via the setup function.

example.lua

@@ -0,0 +1,36 @@
+local Layout = require("nui.layout")
+local Popup = require("nui.popup")
+
+local opts = {
+  buf_options = {
+    filetype = "markdown",
+  },
+  focusable = true,
+  border = {
+    style = "rounded",
+  },
+}
+
+local title_popup = Popup(opts)
+local description_popup = Popup(opts)
+local info_popup = Popup(opts)
+
+local layout = Layout(
+  {
+    position = "50%",
+    relative = "editor",
+    size = {
+      width = "95%",
+      height = "95%",
+    },
+  },
+  Layout.Box({
+    Layout.Box(title_popup, { size = { height = 3 } }),
+    Layout.Box({
+      Layout.Box(description_popup, { grow = 1 }),
+      Layout.Box(info_popup, { size = { height = 15 } }),
+    }, { dir = "col", size = "100%" }),
+  }, { dir = "col" })
+)
+
+layout:mount()