docs: fix typos (#323)

Found via `codespell -L mey,wirth`

Author: kianmeng

test/basic.js

@@ -117,7 +117,7 @@ test('Command line: webtorrent download <torrent file> (with local content)', t
 //   cp.exec(`${CMD} downloadmeta '${fixtures.sintel.magnetURI}' --out ${fixturesPath}`, (err, data) => {
 //     t.error(err)
 //     const parsedTorrent = parseTorrent(fs.readFileSync(`${fixturesPath}/${fixtures.sintel.parsedTorrent.infoHash}.torrent`))
-//     // Sintel torrent file contain two fields not availaible from the DHT
+//     // Sintel torrent file contain two fields not available from the DHT
 //     const expectedTorrent = fixtures.sintel.parsedTorrent
 //     delete expectedTorrent.created
 //     delete expectedTorrent.createdBy

version.cjs

@@ -1,2 +1,2 @@
-// Exports package.json version to work around "with" and "assert" imports for backwards compatability.
+// Exports package.json version to work around "with" and "assert" imports for backwards compatibility.
 module.exports = require('./package.json').version