Coding standard suggestions

When I run the module on phpcs, following errors are listed:

FILE: ...l/drupal-8.4.3/modules/editor_md/src/Plugin/Editor/editor_md.php
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FOUND 15 ERRORS AFFECTING 14 LINES
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   1 | ERROR | [x] The PHP open tag must be followed by exactly one
     |       |     blank line
   2 | ERROR | [x] There must be one blank line after the namespace
     |       |     declaration
  10 | ERROR | [x] There must be one blank line after the last USE
     |       |     statement; 0 found;
  25 | ERROR | [ ] Class name must begin with a capital letter
  25 | ERROR | [ ] Class name must use UpperCamel naming without
     |       |     underscores
  60 | ERROR | [x] Expected 1 blank line before function; 0 found
  65 | ERROR | [x] Expected 1 blank line after function; 0 found
  78 | ERROR | [x] Expected 1 blank line after function; 0 found
  84 | ERROR | [x] TRUE, FALSE and NULL must be uppercase; expected
     |       |     "FALSE" but found "false"
  86 | ERROR | [x] Expected 1 blank line after function; 0 found
  98 | ERROR | [x] Expected 1 blank line after function; 0 found
 104 | ERROR | [x] Expected 1 blank line after function; 0 found
 114 | ERROR | [x] Expected 1 blank line after function; 0 found
 124 | ERROR | [x] Expected 1 blank line after function; 0 found
 125 | ERROR | [x] The closing brace for the class must have an empty
     |       |     line before it
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PHPCBF CAN FIX THE 13 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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