update documentation on fragments

Dependencies

• [2] KKMFQDR4 editing source code from within the app
• [3] TGHAJBES use line cache for drawings as well
• [4] G54H3YG2 get rid of all bifold text
• [5] ILOA5BYF separate data structure for each line's cache data
• [6] LF7BWEG4 group all editor globals
• [7] OI4FPFIN support drawings in the source editor
• [*] 2L5MEZV3 experiment: new edit namespace

Change contents

• replacement in source_edit.lua at line 57
  [2.153575]→[2.153575:153676](∅→∅)
  − -- fragments: snippets of rendered love.graphics.Text, guaranteed to not straddle screen lines
  [2.153575]

  [2.153676]
  + -- fragments: snippets of the line guaranteed to not straddle screen lines
• replacement in edit.lua at line 56
  [3.8031]→[3.8031:8132](∅→∅)
  − -- fragments: snippets of rendered love.graphics.Text, guaranteed to not straddle screen lines
  [3.8031]

  [3.8132]
  + -- fragments: snippets of the line guaranteed to not straddle screen lines