Change "Mac OS X" to "macOS" in documentation

doc/md/Installation_Instructions/macOS-Compile-From-Source-Instructions.md

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+<a id="Top"></a>
+
+# macOS - Compilation from source instructions
+
+# Table of Contents
+- [macOS - Compilation from source instructions](#macos---compilation-from-source-instructions)
+- [Table of Contents](#table-of-contents)
+  - [Follow Homebrew developer instructions](#follow-homebrew-developer-instructions)
+  - [(optional) Running without sudo](#optional-running-without-sudo)
+
+
+## Follow Homebrew developer instructions
+^[Top](#top)
+
+Follow the instructions here [developer instructions](/doc/md/Installation_Instructions/macOS-Homebrew-Installation-Instructions.md#homebrew-macos-developer-installation) and you are done. 
+
+## (optional) Running without sudo
+^[Top](#top)
+
+This section is an *optional* installation procedure. 
+
+
+Assuming you are using the ``bash`` shell (using ``chsh -s /bin/bash `whoami```), we can create 
+an alias to the relevant commands:
+```bash
+export BASHRC="~/.bash_profile"
+export PM3LOCAL_PATH="$(greadlink -f .)"
+touch $BASHRC
+echo "alias pm3=\'$PM3LOCAL_PATH/pm3\'" >> $BASHRC
+echo "alias pm3-flash=\'$PM3LOCAL_PATH/pm3-flash\'" >> $BASHRC
+echo "alias pm3-flash-all=\'$PM3LOCAL_PATH/pm3-flash-all\'" >> $BASHRC
+echo "alias pm3-flash-bootrom=\'$PM3LOCAL_PATH/pm3-flash-bootrom\'" >> $BASHRC
+echo "alias pm3-flash-fullimage=\'$PM3LOCAL_PATH/pm3-flash-fullimage\'" >> $BASHRC
+```
+When you are done running the previous script, make sure to update the settings in your 
+current shell (Mac Terminal) instance by running
+```bash
+source ~/.bash_profile
+```
+When you re-start the Mac terminal, new shell instances will automatically load these 
+new settings.