doc/manual/src/installation.md: give a conf syntax type

Dependencies

• [2] 5DXGOH6Q statsd: add a chance to set hostname and port in hydra.conf
• [3] L4JYZ7BM doc: switch shell session code blocks to `console` type.
• [4] 3JXCTKEC Add markdown files for documentation

Change contents

• replacement in doc/manual/src/installation.md at line 175
  [4.12891]→[3.1109:1113](∅→∅)
  − ```
  [4.12891]

  [3.1113]
  + ```conf
• edit in doc/manual/src/installation.md at line 265
  [4.15610]→[2.218:219](∅→∅)
  −