You can use file explorers for much of this too, and can also
fetch zipfiles in Termux using "curl" (after "pkg install curl"). 

#------------------------------------
# To get the Mergeall-source package
#------------------------------------

<download source zip from learning-python.com/mergeall.html>

$ mkdir /sdcard/work
$ cd /sdcard/work/
$ mv ../Download/Mergeall-source.zip . 
$ unzip -d . Mergeall-source.zip

#------------------------------------
# To get the helper-scripts package
#------------------------------------

<download scripts zip at learning-python.com/mergeall-android-scripts.zip> 

$ cd /sdcard/work/
$ mv ../Download/mergeall-android-scripts.zip . 
$ unzip -d . mergeall-android-scripts.zip

#------------------------------------
# To install the bash profile file
#------------------------------------

$ cd ~
$ cp /sdcard/work/mergeall-android-scripts/your--.bash_profile .
$ mv your--.bash_profile .bash_profile 
$ vi .bash_profile   # or use nano?
$ source .bash_profile
/sdcard/work