At times when working with the terminal I need to repeat myself, thankfully other people before us, solved this for us.
For this, I will use an alias
In computing, alias is a command in various command-line interpreters, which enables a replacement of a word by another string. source wikipedia
To create an alias we need to edit the .bashrc or .zshrc depending on your configuration.
Syntax: alias <shortcut name>= 'command'
eg: alias cdDiathesea='cd $HOME/documents/projects/reacttoy'
now I'll remember how to do it next time.