TODOs from file doesn't show up correctly

Description

When I go to the TODO tab and look at Files category it only shows sections even though I've got many TODOs in them in TODO file in the root of the project.

I also see this error whenever I start vscode in that repository:

This is that error in the console:

![image](https://user-images.githubusercontent.com/20902250/87998753-17039680-caf9-11ea-9584-086e7b29636e.png)

This is that error in text form

``` Error: [fabiospampinato.vscode-todo-plus]: Proposed API is only available when running out of dev or with the following command line switch: --enable-proposed-api fabiospampinato.vscode-todo-plus at a (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:594) at Object.t.checkProposedApiEnabled (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:594) at m.getTooltip (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:611) at m.createTreeNode (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:611) at m.createAndRegisterTreeNode (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:610) at /usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:609 at processTicksAndRejections (/usr/lib/code/out/vs/code/electron-browser/workbench/internal/process/task_queues.js:85) at async Promise.all (/usr/lib/code/out/vs/code/electron-browser/workbench/index 2) onDidChangeNotification @ /usr/lib/code/out/vs/workbench/workbench.desktop.main.js:2946 ```

This is my `TODO` file in the projects root

![image](https://user-images.githubusercontent.com/20902250/87999105-2cc58b80-cafa-11ea-8823-906db9b4a687.png)

In text

``` Discuss: Theo: - Consider using `menus` for pagination instead of custom paginator - Global aiohttp session in bot is nice, but don't use `self.session = self.bot.aiosession` it doesn't make sense, simply use `self.bot.aiosession` directly - Solve issues with azure pipelines not checking branches and being unaccessible on master @today @critical Jana: - Rename `CORE DEV` discord role to `Core Devs` @low - **CodeFactor** detects TODOs in code as mistakes, that shouldn't be the case @today @high * Occured in PR #67 Todo: - Remove `manage_messages` restriction on the `ping` command in `bot/cogs/common.py` @1m Requested by Daneel (https://discordapp.com/channels/716612156975480832/728568693700689980/734868606935892019) - Use `ProcessedMember` in `bot/cogs/commands.py` inside of `userinfo` command @5m - Embed reset doesn't reset field IDs @30m - Use custom User -> Member convertion on `bot/cogs/games/tic_tac_toe.py` in `on_reaction_add` Code styling: - Rename all embeds in `bot/cogs/fun.py` to `embed` instead of `em` or `e` or something else @15m Pending (Tic Tac Toe): - Implement AI logic for Tic Tac Toe (`update-fun` branch, `bot/cogs/games/tic_tac_toe.py`) @2h - Use better embed format for Tic Tac Toe (`update-fun` branch, `bot/cogs/games/tic_tac_toe.py`) @10m ✔ Refactor Tic Tac Toe @est(2h) @started(20-07-20 23:30) @done(20-07-21 02:12) @lasted(2h42m27s) ```

Even though it shows the categories shouldn't it also show the individual tasks? Also, 2 nested categories from Todo category are missing, I'm not sure what's wrong here

System and VSCode Details

Another error I've noticed

I've also noticed 1 more minor error where when I don't have anything under Archive: category it doesn't show anything in the Files tab at all, I'd appreciate it if there was some kind of descriptive error popup saying what's wrong or somehow displaying it even with categories without any items.

The image of this can be seen here

![image](https://user-images.githubusercontent.com/20902250/87998617-b83e1d00-caf8-11ea-860f-96fb11ad9174.png)

fabiospampinato / vscode-todo-plus