OC-5070: Clarify some points about discoveries/budgets and link to two better templates

This introduces the following changes:

• mention equivalence between discovery and epic
• explain whom do we write for
• type of language expected (non-technical)
• extra: asks to refer to the client by name
• some new points to always include
• ensure that management/CEO/CTO time is covered
• link to a template with common requests (list of standard work)
• link to flow chart
• include results from forum discussions ← (not many conclusions, just the flow chart and the spreadsheets)
• new: ask to use separate spreadsheet for numbers
• in addition, the Markdown template was moved into the Google Docs template → the new template is at a new location https://docs.google.com/document/d/12U-WQY_h2FO0UgCybKdcgoaJwaDAYG4uvyn_ZhQfCbM/edit#, please review (if approved, -the content must be copy-pasted into the official file- just rename the file. We'll keep the old template https://docs.google.com/document/d/1NMUYRe7cJRs7yiMGg94A7k1h5HGKTaI0ayPcG2K9kJU/edit as a generic template)
• in addition, a new spreadsheet template was created: https://docs.google.com/spreadsheets/d/12AsYspuinZ0Y7nCRrRd85aOK8MCR1t1IG0L9TWlMYfI/edit#gid=0, please review (if approved, the file must be renamed; the link won't change)

@antoviaque After the templates are finished I'll do those renames.