Removed tabs and replaced with spaces, fixed error with $no_backup wa…

[jordantrizz]

There were some leftover tabs that I turned into spaces, some were from my previous comment and some weren't.

An error was generated when using --insert due to $no_backup not being defined. Fixed this by adding $no_backup=no when using --insert

This revealed another issue with checking if $no_backup is null, changed to if = no.

When no "src" was defined on the command line, the script would simply print "Created by gh-md-toc" which isn't helpful. Instead put in the following check, if $src is null utilize README.md as the default file to use. If it doesn't exist it will fail with file not found.

[axeljonson]

Hi @jordantrizz I don't think this going to get you what you are expecting. Placing no_backup="yes" on line 272 will cause the "--insert" and "--no_backup" CLI options to be dependent and that may not be what folks want or expect. Just because I want to insert the TOC does not necessarily mean I don't want a backup. To keep them independent, you may want to remove this line and add the following:
line 233: local no_backup="no"
And then change line 182 as follows:
from:
if [ -z $no_backup ]; then
to:
if [ $no_backup = "no" ], then

I think this will keep the two CLI options independent and the code will provide the expected results.

[jordantrizz]

Totally, wish I had time to commit to this but I don't :(

[zeitounator]

This has been fixed differently in #108

[ekalinin]

Please, fix the conflict.

[jordantrizz]

Please, fix the conflict.

If I get some spare cycles I will be able to address the issue. Sorry!