Add note to clarify usage of angle brackets

Add note explaning the angle brackets are included
in the make command or that they could also be
exchanged for escaped double quotes.

Signed-off-by: Thomas Daubney <[email protected]>

Author: tom-daubney-arm

kb/compiling-and-building/how-do-i-configure-mbedtls.md

@@ -22,7 +22,7 @@ The `config.py` script automatically finds the `mbedtls_config.h` file when it r
 
 ## Alternative configuration files
 
-You might want to keep the custom configuration file for your application outside the Mbed TLS source tree. You can do this by defining the macro `MBEDTLS_CONFIG_FILE` for the desired filename (including the quote or angular brackets) at compile time. For example, using **make**:
+You might want to keep the custom configuration file for your application outside the Mbed TLS source tree. You can do this by defining the macro `MBEDTLS_CONFIG_FILE` for the desired filename (including the quote or angular brackets) at compile time. For example, using **make**: (Note: The angle brackets `<>` are included in the command, but they could be replaced with properly escaped double quotes `\"\"`.)
     ```
      CFLAGS="-Ipath/to/config -DMBEDTLS_CONFIG_FILE='<my_config.h>'" make
     ```