Various changes

A couple of 'style changes' I guess you could call them.
- I've tried to make all references to PowerShell command within the text Courier
- I've used ... for sentence interrupted by snippets of indentede code

DOC-02 Minor re-wording
DOC-03 Changed 'Provide usage examples' to 'Provide Examples'
DOC-05 Removed a couple of sentences
DOC-06 Removed the last sentence. Changed title to 'Comment your code...'
DOC-07 Changed title to '...but don't over-comment'. And removed a couple of sentences.
VER - amended the overall section title from 'Versioning' to 'Powershell Version' . I think 'Versioning' sounds like it's to do with version control.
VER-01 Removed a couple of sentences
PERF-02 Re-hashed this section a bit. It's now shorter, although given where the page breaks this may not have been necessary
READ-01 Removed 3 or 4 sentences
READ-01 Added in that you should use either style of bracket-ing but not both. Must admit I often use both....
TOOL-01 Removed last sentences
TOOL-07 Removed last paragraph (about views and modules)
PURE-02 Bolded the 4 options
PURE-04 Removed the 'ignorance is no excuse' paragraph
ERR - changed section title to 'Error Handling'. Original title is stronger but it doesn't fit in 6 inches
WAST-01 removed some of the reference to community and the 'ignorance is no excuse' paragraph

Also:
I removed the One-Liners section
I removed the Powershell Way section

The majority of the changes here were to shorten the text down towards 20 page, but some are an attempt to further clarify.

I've left the TOC in for the time being. I think there's some value in the quick reference aspect of it, but I don't know.