Add smart cells livebook app

public-apps/smart_cells.livemd

@@ -0,0 +1,74 @@
+<!-- livebook:{"app_settings":{"access_type":"public","auto_shutdown_ms":3600000,"output_type":"rich","show_source":true,"slug":"livebook-smart-cells-list","zero_downtime":true}} -->
+
+# List of Livebook Smart Cells on Github
+
+```elixir
+Mix.install([
+  {:kino, "~> 0.12"},
+  {:req, "~> 0.4"},
+  {:req_github_paginate, github: "acalejos/req_github_paginate"}
+])
+```
+
+## Section
+
+```elixir
+defmodule GitHubAPI do
+  def headers(),
+    do: %{
+      "Accept" => "application/vnd.github+json",
+      "Authorization" => "Bearer #{System.fetch_env!("LB_GITHUB_TOKEN")}",
+      "X-GitHub-Api-Version" => "2022-11-28"
+    }
+
+  def params(),
+    do: [
+      q: "use Kino.SmartCell in:file language:elixir",
+      per_page: 100,
+      page: 1
+    ]
+
+  def new() do
+    Req.new(base_url: "https://api.github.com") |> ReqGitHubPaginate.attach()
+  end
+
+  def _get_all(request, params) do
+    resp =
+      Req.get!(
+        request,
+        url: "/search/code",
+        params: params,
+        headers: headers()
+      )
+
+    if Keyword.has_key?(resp.headers["link"], :next) do
+      {_, params} = Map.pop(resp.headers["link"][:next], "url")
+      resp.body["items"] ++ _get_all(request, params)
+    else
+      resp.body["items"]
+    end
+  end
+
+  def get_all(request) do
+    _get_all(request, params())
+  end
+end
+```
+
+```elixir
+items = GitHubAPI.new() |> GitHubAPI.get_all()
+nil
+```
+
+```elixir
+for repo <- items, repo["repository"]["owner"]["login"] != "livebook-dev" do
+  %{
+    "Name" => repo["repository"]["name"],
+    "Description" => repo["repository"]["description"],
+    "URL" => repo["repository"]["html_url"]
+  }
+end
+|> Kino.DataTable.new(name: "Smart cells")
+```
+
+<!-- livebook:{"offset":1656,"stamp":{"token":"XCP.UQKFeTQkO9H-qhsO_ThypqbD1bal4zBCrCVmJb1odeGBZWy0CRpRuEKYQxsySyhsEHNurHX68ZQO3WXdmGn2IrQl_5LBcCztAgyKBJY11b4Cw1ksj_RS","version":2}} -->