feat: Support subscribe GitHub file commits (#2002)

* feat: Support subscribe github single file

* refact: Use GitHub API to crawl commits

* Use GitHub API to crawl commits
* Update document

* Add access_token for github file commits api

lib/routes/github/file.js

@@ -0,0 +1,47 @@
+const axios = require('../../utils/axios');
+const config = require('../../config');
+
+module.exports = async (ctx) => {
+    const user = ctx.params.user;
+    const repo = ctx.params.repo;
+    const branch = ctx.params.branch;
+    const filepath = ctx.params.filepath;
+
+    const fileUrl = `https://github.com/${user}/${repo}/commits/${branch}/${filepath}`;
+
+    const reqParams = {
+        sha: branch,
+        path: filepath,
+    };
+    if (config.github.access_token) {
+        reqParams.access_token = config.github.access_token;
+    }
+
+    const res = await axios.get(`https://api.github.com/repos/${user}/${repo}/commits`, {
+        params: reqParams,
+    });
+    const list = res.data;
+    const count = [];
+    for (let i = 0; i < Math.min(list.length, 10); i++) {
+        count.push(i);
+    }
+    const resultItems = await Promise.all(
+        count.map(async (i) => {
+            const each = list[i];
+            const item = {
+                title: each.commit.message.split('\n')[0],
+                description: `<pre>${each.commit.message}</pre>`,
+                link: each.html_url,
+                author: each.commit.author.name,
+                pubDate: new Date(each.commit.committer.date).toUTCString(),
+            };
+            return Promise.resolve(item);
+        })
+    );
+
+    ctx.state.data = {
+        title: `GitHub File - ${user}/${repo}/${branch}/${filepath}`,
+        link: fileUrl,
+        item: resultItems,
+    };
+};