Support more plaintext filetypes (#757)

* Add more plaintext document types

org-mode, asciidoc, and reStructuredText are all text formats

Signed-off-by: Christian Romney <christian.a.romney@gmail.com>

* lint

---------

Signed-off-by: Christian Romney <christian.a.romney@gmail.com>
Co-authored-by: Christian Romney <christian.a.romney@gmail.com>

collector/utils/constants.js

 const WATCH_DIRECTORY = require("path").resolve(__dirname, "../hotdir");
 
 const ACCEPTED_MIMES = {
-  "text/plain": [".txt", ".md"],
+  "text/plain": [".txt", ".md", ".org", ".adoc", ".rst"],
   "text/html": [".html"],
 
   "application/vnd.openxmlformats-officedocument.wordprocessingml.document": [
@@ -27,6 +27,10 @@ const ACCEPTED_MIMES = {
 const SUPPORTED_FILETYPE_CONVERTERS = {
   ".txt": "./convert/asTxt.js",
   ".md": "./convert/asTxt.js",
+  ".org": "./convert/asTxt.js",
+  ".adoc": "./convert/asTxt.js",
+  ".rst": "./convert/asTxt.js",
+
   ".html": "./convert/asTxt.js",
   ".pdf": "./convert/asPDF.js",