fix: Category titles should use one instead of multiple spaces.

[michael-simons]

See the title. If this has been done in purpose (two blanks), please just close it.

If you keep it two and someone wants to adapt their categories and one uses 1 space instead of two, 0.9.1 fails with:

JReleaser for project neo4j-migrations-parent has not been properly configured.: JReleaser has not been properly configured.
[ERROR] java.util.MissingResourceException: Can't find resource for bundle java.util.PropertyResourceBundle, key validation_ares_missing
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

[CLAassistant]

All committers have signed the CLA.

[aalmiray]

I believe the 2 spaces were needed because otherwise the chosen emojis would appear next to the title. I'll look again if that's actually true.

Also the missing validation key has a typo: 'ares'. Need to fix that.

[aalmiray]

Thank you @michael-simons. I think the underlying problem was that the category used the title for both identification and render. These two responsibilities have been split by #619 allowing you to change the rendering on your own project if needed.

The 2 spaces between emoji and text found in some of the categories are actually needed.