Fix for #801: enable imports for sites that are using git submodules

[deining]

Unfortunately, #801 did not work as expected. This PR will fix these issues, sorry for any inconvenience caused!

Note:: Inside the [module] section, this fix makes use of the replacements configuration setting:

[module]
# imports should not apply for sites that are using git submodules 
replacements = "github.com/FortAwesome/Font-Awesome -> ., github.com/twbs/bootstrap -> ."

Replacements is available as of hugo version 0.77.

Currently the user guide states:

You need a recent extended version (we recommend version 0.75.0 or later) of Hugo

Therefore with this patch we are raising minimum required hugo version from 0.75 to 0.77 (mandatory now). I hope this is o.k.
This PR updates the user guide accordingly.

[LisaFC]

Thanks for the prompt fix!

[rogerioesteves]

When I added Docsy in my project the last version of docsy is not working. I get the error "Error: module "github.com/FortAwesome/Font-Awesome" not found".

Was fixed this problem? Whats the work around?

[deining]

When I added Docsy in my project the last version of docsy is not working. I get the error "Error: module "github.com/FortAwesome/Font-Awesome" not found".

Was fixed this problem? Whats the work around?

Workaround:

• navigate to your themes folder
• create two new directory structures (empty directories):

mkdir -p github.com/twbs/bootstrap
mkdir -p github.com/FortAwesome/Font-Awesome

Does this cure your problem?