[CP-288] Update secureboot documentation

Update documentation about secureboot

Signed-off-by: Lucjan Bryndza <lucjan.bryndza@mudita.com>

[BH-375] Clean `module-utils/third-party`

Clean `module-utils/third-party`

[EGD-6212] Add tethering doc

This commit adds list of currently supported systems that are
check for working with tethering. Rest of the doc will be updated
with another commit

[EGD-7131] Flashing instruction updated

Flashing instruction for MacOS and Windows updated.

[BH-363] Move libphonenumber to a separate directory

Move libphonenumber to a separate directory

Merge branch 'master' into stable

[BH-353] Add Documentation for main targets

* clean up mimimu required cmake version
* fixes for release workflow

Add documentation for targets, fixes for cmake
and release workflow.

Merge branch 'master' into stable

[BH-353] Add minimal build target for BH

* add BellHybridMain
* fixing post review

Git automatically converts BellHybird as move from source/main.cpp to
prevent this and maintain "main.cpp" history adding new target as
separate commit.

[BH-360] Move TPLIB re2 to separate dir

Changed submodule directory and updated cmake scripts.
Updated paths in PureCoverage script and Doxyfile

Merge branch 'master' into stable

[BH-357] Move protobuf to third-party dir

* Use the CMakeLists.txt from lib authors.
* Disable building libprotobuf in the all target.
* Disable warnings in the libprotobuf-lite target.

[BH-397] Move TPLIB parallel-hashmap

Changed submodule directory and changed way its linked,
in order to use target_link_libraries checkouted phmap
dependency to the newest revision which includes small
cmake fixes (see 031d214f2ce1973933abdf2a998d986ff8094d8e),
updated paths in PureCoverage script and Doxyfile

[EGD-6728] Documentation cleanup

Cleanup acc. to guidelines created in EGD-6632.

[BH-351] Simulator input handling

Add Keyboard binding for Linux Bell simulator

[EGD-6258] Add CMake options to the Quick Start

Added description of CMake options used during generation

[EGD-6537] Create Jenkins CI

Try to fix GitHub problems by switching to Jenkins CI system.

[EGD-6355] Adjust MuditaOS to be used with Secure Boot

The start address of the OS image adjusted to comply with HAB
Secure Boot. Proper SNVS initialization performed at system startup.
SNVS drivers updated to most recent version. Image signing can be
performed as a part of build process. See doc/secure_boot.md for
more info.

[EGD-6554] Fix emulator to simulator

Fixed every mention of emulator to simulator - in
docs and shell scripts.

[EGD-6515] Answer/reject calls using headset

Clean up propagation of headset keys events
Clean up volume control with headset keys
Update key mappings for simulator
Use headset OK key to answer/reject calls