Fix shellcheck issues in home/.zshrc
Fix shellcheck issues in home/.zshrc

Fixes problems detected by the shellcheck Linter.

Right now, shellcheck doesn't limit my options in zsh, but there will
come a time when I may have problems with it, so don't forget about it.

https://github.com/koalaman/shellcheck/issues/809

The command was executed:
```
shellcheck --source-path=home --external-sources home/.zshrc
```

The result was received:
```
In home/.zshrc line 1:
^-- SC2148: Tips depend on target shell and yours is unknown. Add a shebang.

In home/.zshrc line 11:
ZSH_THEME="suvash"
^-------^ SC2034: ZSH_THEME appears unused. Verify use (or export if used externally).

In home/.zshrc line 71:
plugins=(
^-----^ SC2034: plugins appears unused. Verify use (or export if used externally).

In home/.zshrc line 80:
source $ZSH/oh-my-zsh.sh
       ^---------------^ SC1090: Can't follow non-constant source. Use a directive to specify location.
       ^--^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean:
source "$ZSH"/oh-my-zsh.sh

In home/.zshrc line 111:
  [ -r "$file" ] && [ -f "$file" ] && source "$file"
                                             ^-----^ SC1090: Can't follow non-constant source. Use a directive to specify location.

For more information:
  https://www.shellcheck.net/wiki/SC2148 -- Tips depend on target shell and y...
  https://www.shellcheck.net/wiki/SC1090 -- Can't follow non-constant source....
  https://www.shellcheck.net/wiki/SC2034 -- ZSH_THEME appears unused. Verify ...
```

By-Vasiliy/dotfiles,By-Vasiliy/dotfiles