Optional/mandatory whitespace in §5.5 Advanced line types

[Nathan Galt]

Prior reading:

=> https://gemini.circumlunar.space/docs/specification.html The Spec, ?5.5 Advanced line types

I noticed that the spec has three different advanced line types and three different whitespace handling verbiages for each.

Heading lines: Start with 1?3 ?#?, then optional whitespace.
List items: Start with ?* ? (note the space!)
Quote lines: Start with ?>? 

Shouldn?t these three have the same whitespace rules, with the same phrasing?

Here?s my argument for ?mandatory whitespace for all? ([\t ]+):

- It lets authors write ?#3. I like eggs.? without accidentally getting that line parsed as if it were a heading (we don?t have backslash escapes like Markdown does)
- It?s better for some emoticons that, um, might be out there that start with > or *
- ?#Steak? looks like a hashtag, and I could see some fraction of authors writing ?#blah? _meaning_ for it to be a tag
- We shouldn?t be worried about backcompat at v0.14.2. I don?t have much gemini text, but I?m the sort who would reformat his own non-conformant documents to match something like this.

- - - -

I could see myself wanting an H4-equivalent or higher, but I?m not certain this is _quite_ the right time to mention it. Also the current spec already seems to say that clients should parse ?#### Eggs? as not-a-heading.