Standardize README with documented best-practices

@ankushgautam76@gmail.com, not sure why you patched

-    $country_name = $this->getCountryName($country_code);
+    //$country_name = $this->getCountryName($country_code);

which seems to be QUITE vital. Corrected your #2 patch.
Extra suggestion, create different issues to solve different problems (readme and coding standards) or create a single patch for the both. With 2 different patches on same issues is easy to make mistakes (or at least it is for me).

Extra suggestion, create different issues to solve different problems (readme and coding standards) or create a single patch for the both

+1 to this. Grouping different fix types in one issue is problematic and muddling, and makes the work of our contributors more hectic.

Moving code standards into its own issue: #3138236: Drupal Coding Standards Fixes

Overall, the one line spacing after the first sentence in a paragraph needs to be removed document-wide.

The REQUIREMENTS section needs work. Some of this would likely be applicable under RECOMMENDED MODULES, where some of this is CONFIGURATION/setup. REQUIREMENTS should be formatted a la https://www.drupal.org/node/2181737#requirements . The REQUIREMENTS should list the requirements as seen https://git.drupalcode.org/project/taxonomy_place/-/blob/8.x-1.x/taxonom... .

In fact, some of what is in REQUIREMENTS is doubly listed in CONFIGURATION, so that should be merged (what's required and optional).

All unordered lists should be converted to * per the README template: https://www.drupal.org/node/2181737 , and spaced appropriately (1 space). Text wrapping on lists should meet the first character of the list item, not the bullet/item icon.

I added some enhancements after committing this. Thanks!