I just have a simple header for each day:

   # 09/05/2020
   Today I mostly ate cake

   ## Discoveries
   ## Meetings
   ## Projects
   - Worked on project 1
     - Fixed issue <link>
     - TODO: Bugfix #1234
   ## Misc

So a fixed set of headers for each day "Projects", "Meetings", "Discoveries", "Misc", and free-form text. Sometimes I copy/paste commands and output.

Searching is pretty much just grep.

More detail here https://blog.steve.fi/keeping_a_simple_markdown_work_log__vi...