What is the purpose of the .angulardoc.json file in an angular project?

I have been generating new Angular projects before now and I have never seen an .angulardoc.json file in the folder in which I generated my Angular project.

Recently, I upgraded my angular Cli to the following

Angular CLI: 9.0.1
Node: 12.13.0
OS: win32 x64

Angular: 9.0.0
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router
Ivy Workspace: Yes

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.900.1
@angular-devkit/build-angular     0.900.1
@angular-devkit/build-optimizer   0.900.1
@angular-devkit/build-webpack     0.900.1
@angular-devkit/core              9.0.1
@angular-devkit/schematics        9.0.1
@angular/cli                      9.0.1
@ngtools/webpack                  9.0.1
@schematics/angular               9.0.1
@schematics/update                0.900.1
rxjs                              6.5.4
typescript                        3.7.5
webpack                           4.41.2

and now when I generate a new project, I see a .angulardoc.json file in the same folder with the folder in which I my project was generated.

The file contains an object with two keys: repoId which has the value of an auto-generated key, and lastSync which has the value of 0 for now.

What is the purpose of this file? Is this a VSCode thing or an Angular thing?