[PATCH 1/2] doc: add supported host distro section

["Maxim Yu. Osipov" <mosipov@ilbers.de>]

Signed-off-by: Maxim Yu. Osipov <mosipov@ilbers.de>
---
 doc/user_manual.md | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/doc/user_manual.md b/doc/user_manual.md
index 058f7bd..213ca69 100644
--- a/doc/user_manual.md
+++ b/doc/user_manual.md
@@ -1,6 +1,6 @@
 # ISAR User Manual
 
-Copyright (C) 2016-2017, ilbers GmbH
+Copyright (C) 2016-2018, ilbers GmbH
 
 ## Contents
 
@@ -29,6 +29,11 @@ Isar provides:
  - Native compilation: Packages are compiled in a `chroot` environment using the same toolchain and libraries that will be installed to the target filesystem.
  - Product templates that can be quickly re-used for real projects.
 
+### Supported Host Distributions
+
+ - `Debian`: 8.x (jessie), 9.x (stretch)
+ - `Ubuntu`: 16.04 LTS
+
 ---
 
 ## Getting Started
@@ -83,11 +88,15 @@ Isar requires `sudo` rights without password to work with `chroot` and `debootst
 ```
  # visudo
 ```
-In the editor, allow the current user to run sudo without a password, e.g.:
+In the editor, allow the current user to run sudo without a password.
+One have to add two entries to sudoers (one for user, another - for user's primary group), e.g.:
+
 ```
- <user>  ALL=NOPASSWD: ALL
+<user>	ALL=NOPASSWD: ALL
+
+%<user>	ALL=NOPASSWD: ALL
 ```
-Replace `<user>` with your user name. Use the tab character between the user name and parameters.
+Replace `<user>` with your user/primary group name. Use the tab character between the user name and parameters.
 
 ### Check out Isar
 
-- 
2.11.0