merge two sections into Semantic versioning and upgrades + remove obvious requiremts/recommendations + rename the compatibility section

Added tag v0.3 for changeset 8da11cce2c98

add TXT output + change directory structure

remove superfluous whitespace

GNU GPLv3 compatibility is required

Semantic versioning is required

fix links/anchors

make: statistics (just for fun) generates output: chapter: ╭──────────────────────────────────┬──────────────────────╮ │ name (string) │ item_count (integer) │ ├──────────────────────────────────┼──────────────────────┤ │ Free software │ 7 │ │ Documented │ 5 │ │ Semantic versioning │ 5 │ │ Compatible with itself │ 6 │ │ Compatible with others │ 6 │ │ Modular architecture │ 4 │ │ Extensible │ 7 │ │ Testable │ 4 │ │ Safe code and sustainability │ 6 │ │ Small code footprint │ 3 │ │ Sane dependencies │ 10 │ │ Easily auditable │ 3 │ │ Reproducible builds │ 2 │ │ Trustworthy packages and sources │ 6 │ │ Network interactions │ 4 │ │ Localized/internationalized │ 11 │ │ Communication channels │ 23 │ │ Accept contributions │ 13 │ │ Open development – has public: │ 4 │ ╰──────────────────────────────────┴──────────────────────╯ Record count: 19

some cleanup and clarifications

make: publish