Add docs code testing & documentation syntax changes (#196)

- Creates testing files `md_testing.py` and `md_testing.js` for testing
python and nodejs code in markdown files in the documentation
This listens for HTML tags as well: `<!--[language] code code
code...-->` will create a set-up file to create some mock tables or to
fulfill some assumptions in the documentation.
- Creates a github action workflow that triggers every push/pr to
`docs/**`
- Modifies documentation so tests run (mostly indentation, some small
syntax errors and some missing imports)

A list of excluded files that we need to take a closer look at later on:
```javascript
const excludedFiles = [
  "../src/fts.md",
  "../src/embedding.md",
  "../src/examples/serverless_lancedb_with_s3_and_lambda.md",
  "../src/examples/serverless_qa_bot_with_modal_and_langchain.md",
  "../src/examples/youtube_transcript_bot_with_nodejs.md",
];
```
Many of them can't be done because we need the OpenAI API key :(.
`fts.md` has some issues with the library, I believe this is still
experimental?

Closes #170

---------

Co-authored-by: Will Jones <willjones127@gmail.com>

docs/test/md_testing.js

@@ -0,0 +1,51 @@
+const glob = require("glob");
+const fs = require("fs");
+const path = require("path");
+
+const excludedFiles = [
+  "../src/fts.md",
+  "../src/embedding.md",
+  "../src/examples/serverless_lancedb_with_s3_and_lambda.md",
+  "../src/examples/serverless_qa_bot_with_modal_and_langchain.md",
+  "../src/examples/youtube_transcript_bot_with_nodejs.md",
+];
+const nodePrefix = "javascript";
+const nodeFile = ".js";
+const nodeFolder = "node";
+const globString = "../src/**/*.md";
+const asyncPrefix = "(async () => {\n";
+const asyncSuffix = "})();";
+
+function* yieldLines(lines, prefix, suffix) {
+  let inCodeBlock = false;
+  for (const line of lines) {
+    if (line.trim().startsWith(prefix + nodePrefix)) {
+      inCodeBlock = true;
+    } else if (inCodeBlock && line.trim().startsWith(suffix)) {
+      inCodeBlock = false;
+      yield "\n";
+    } else if (inCodeBlock) {
+      yield line;
+    }
+  }
+}
+
+const files = glob.sync(globString, { recursive: true });
+
+for (const file of files.filter((file) => !excludedFiles.includes(file))) {
+  const lines = [];
+  const data = fs.readFileSync(file, "utf-8");
+  const fileLines = data.split("\n");
+
+  for (const line of yieldLines(fileLines, "```", "```")) {
+    lines.push(line);
+  }
+
+  if (lines.length > 0) {
+    const fileName = path.basename(file, ".md");
+    const outPath = path.join(nodeFolder, fileName, `${fileName}${nodeFile}`);
+    console.log(outPath)
+    fs.mkdirSync(path.dirname(outPath), { recursive: true });
+    fs.writeFileSync(outPath, asyncPrefix + "\n" + lines.join("\n") + asyncSuffix);
+  }
+}