added initial version of frequently asked questions page (#1682)

* added initial version of frequently asked questions page

* fixed codacy

* Update cvat/apps/documentation/faq.md

* added toc

* Update cvat/apps/documentation/faq.md

* Update cvat/apps/documentation/faq.md

* Update cvat/apps/documentation/faq.md

* fix typo

* udpate faq
Co-authored-by: NNikita Manovich <40690625+nmanovic@users.noreply.github.com>

README.md

@@ -24,6 +24,7 @@ Try it online [cvat.org](https://cvat.org).
 - [Command line interface](utils/cli/)
 - [XML annotation format](cvat/apps/documentation/xml_format.md)
 - [AWS Deployment Guide](cvat/apps/documentation/AWS-Deployment-Guide.md)
+- [Frequently asked questions](cvat/apps/documentation/faq.md)
 - [Questions](#questions)
 
 ## Screencasts

cvat/apps/documentation/faq.md

+# Frequently asked questions
+- [How to update CVAT](#how-to-update-cvat)
+- [Kibana app works, but no logs are displayed](#kibana-app-works-but-no-logs-are-displayed)
+- [How to change default CVAT hostname or port](#how-to-change-default-cvat-hostname-or-port)
+- [How to configure connected share folder on Windows](#how-to-configure-connected-share-folder-on-windows)
+- [How to make unassigned tasks not visible to all users](#how-to-make-unassigned-tasks-not-visible-to-all-users)
+- [Can Nvidia GPU be used to run inference with my own model](#can-nvidia-gpu-be-used-to-run-inference-with-my-own-model)
+
+## How to update CVAT
+Before upgrading, please follow the official docker
+[manual](https://docs.docker.com/storage/volumes/#backup-restore-or-migrate-data-volumes) and backup all CVAT volumes.
+
+To update CVAT, you should clone or download the new version of CVAT and rebuild the CVAT docker images as usual.
+```sh
+docker-compose build
+```
+and run containers:
+```sh
+docker-compose up -d
+```
+
+Sometimes the update process takes a lot of time due to changes in the database schema and data.
+You can check the current status with `docker logs cvat`.
+Please do not terminate the migration and wait till the process is complete.
+
+## Kibana app works, but no logs are displayed
+Make sure there aren't error messages from Elasticsearch:
+```sh
+docker logs cvat_elasticsearch
+```
+If you see errors like this:
+```sh
+lood stage disk watermark [95%] exceeded on [uMg9WI30QIOJxxJNDiIPgQ][uMg9WI3][/usr/share/elasticsearch/data/nodes/0] free: 116.5gb[4%], all indices on this node will be marked read-only
+```
+You should free up disk space or change the threshold, to do so check: [Elasticsearch documentation](https://www.elastic.co/guide/en/elasticsearch/reference/6.8/disk-allocator.html).
+
+## How to change default CVAT hostname or port
+The best way to do that is to create docker-compose.override.yml and override the host and port settings here.
+
+version: "2.3"
+```yaml
+services:
+  cvat_proxy:
+    environment:
+      CVAT_HOST: example.com
+    ports:
+      - "80:80"
+```
+
+Please don't forget to include this file in docker-compose commands
+using the `-f` option (in some cases it can be omitted).
+
+## How to configure connected share folder on Windows
+Follow the Docker manual and configure the directory that you want to use as a shared directory:
+- [Docker toolbox manual](https://docs.docker.com/toolbox/toolbox_install_windows/#optional-add-shared-directories)
+- [Docker for windows (see FILE SHARING section)](https://docs.docker.com/docker-for-windows/#resources)
+
+After that, it should be possible to use this directory as a CVAT share:
+```yaml
+version: "2.3"
+
+services:
+  cvat:
+    volumes:
+      - cvat_share:/home/django/share:ro
+
+volumes:
+  cvat_share:
+    driver_opts:
+      type: none
+      device: /d/my_cvat_share
+      o: bind
+```
+
+## How to make unassigned tasks not visible to all users
+Set [reduce_task_visibility](../../settings/base.py#L424) variable to `True`.
+
+## Can Nvidia GPU be used to run inference with my own model
+Nvidia GPU can be used to accelerate inference of [tf_annotation](../../../components/tf_annotation/README.md) and [auto_segmentation](../../../components/auto_segmentation/README.md) models.
+
+OpenVino doesn't support Nvidia cards, so you can run your own models only on CPU.