[readme] add commands to help troubleshoot without closing the current shell

Co-authored-by: artforlife <artforlife@users.noreply.github.com>
Co-authored-by: Sladyn Nunes <sladynnunes98@gmail.com>

README.md

@@ -89,6 +89,15 @@ Eg: `curl ... | NVM_DIR="path/to/nvm"`. Ensure that the `NVM_DIR` does not conta
 #### Troubleshooting on Linux
 
 On Linux, after running the install script, if you get `nvm: command not found` or see no feedback from your terminal after you type `command -v nvm`, simply close your current terminal, open a new terminal, and try verifying again.
+Alternatively, you can run run the following commands for the different shells on the command line:
+
+*bash*: `source ~/.bashrc`
+
+*zsh*: `source ~/.zhrc`
+
+*ksh*: `. ~/.profile`
+
+These should pick up the `nvm` command.
 
 #### Troubleshooting on macOS
 
@@ -98,11 +107,13 @@ If you get `nvm: command not found` after running the install script, one of the
 
   - Since macOS 10.15, the default shell is `zsh` and nvm will look for `.zshrc` to update, none is installed by default. Create one with `touch ~/.zshrc` and run the install script again.
 
-  - If you use bash, the previous default shell, run `touch ~/.bash_profile` to create the necessary profile file if it does not exist.
+  - If you use bash, the previous default shell, your system may not have a `.bash_profile` file where the command is set up. Create one with `touch ~/.bash_profile` and run the install script again. Then, run `source ~/.bash_profile` to pick up the `nvm` command.
+
+  - You have previously used `bash`, but you have `zsh` installed. You need to manually add [these lines](#manual-install) to `~/.zshrc` and run `. ~/.zshrc`.
 
   - You might need to restart your terminal instance or run `. ~/.nvm/nvm.sh`. Restarting your terminal/opening a new tab/window, or running the source command will load the command and the new configuration.
 
-  - You have previously used `bash`, but you have `zsh` installed. You need to manually add [these lines](#manual-install) to `~/.zshrc` and run `. ~/.zshrc`.
+  - If the above didn't help, you might need to restart your terminal instance. Try opening a new tab/window in your terminal and retry.
 
 If the above doesn't fix the problem, you may try the following: