Reference for future: fix Missing X11... and OPENSSL

- ERROR
```
CMake Error at /usr/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
Could NOT find X11 (missing: X11_X11_INCLUDE_PATH X11_X11_LIB)
```

Can be fixed by the following:

```apt install libx11-dev```
```apt install libx11-dev```

- Error: SSL
```
Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the
system variable OPENSSL_ROOT_DIR (missing: OPENSSL_CRYPTO_LIBRARY
OPENSSL_INCLUDE_DIR)
```

```sudo apt-get install libssl-dev```

Review the CMake error output for missing X11 and OpenSSL dependencies and verify the listed apt packages on the affected system. Document the two troubleshooting steps in the repository's appropriate documentation location; done means a newcomer can use the recorded commands to resolve both errors.

Written by the indexing model from the issue text.