[*] update readme.md

README.md

+### Build from sources:
+
+#### Linux Prerequsites 
+
+To successfully complete of the build, you need to have the following packages to be installed 
+(packages are named as in Debian GNU/Linux 10 "buster", please found the corresponding packages for your distribution):
+
+* libsqlite3-dev
+* libmagic-dev
+* libz-dev
+* traceroute
+* build-essential
+* cmake
+* dpkg-dev
+* debconf-utils
+
+Please use the command below to install dependencies listed above
+```
+sudo apt-get install build-essential cmake dpkg-dev libz-dev libmagic-dev libsqlite3-dev traceroute debconf-utils xsltproc
+```
+
+Generaly thats all what you need
+
+
+#### Get all cellframe-tool-sign sources
+
+This command fetch sources from gitlab and build them. 
+  ```
+  git clone https://gitlab.demlabs.net/cellframe/cellframe-tool-sign.git --recursive
+  ```
+
+#### Build cellframe using cmake framework
+Get into directory with cellframe-tool-sign and execute the following commands
+  ```
+  mkdir build
+  cd build
+  cmake ../
+  make -j$(nproc)
+  ```
+*-j$(nproc)* nrpoc parameter depends on your machine capacity - number of processor cores.
+As a result, you should be able to fine make files in your build folder which will be used by cpack command to create an installation package.
+