Tweak docs

doc/src/usage.md

@@ -76,7 +76,9 @@ In Markdown and Noweb input formats documentation chunks are the parts that aren
 
 Markdown code chunks are defined using fenced code blocks with options following on the same line. e.g. to hide code from output you can use:
 
-` ```julia; echo=false`
+```
+ ```julia; echo=false`
+```
 
 [Sample document]( https://github.com/mpastell/Weave.jl/blob/master/examples/FIR_design.jmd)
 
@@ -152,7 +154,7 @@ options:
 ---
 ```
 
-You can also set format specific options. Here is how to set different out_path for `md2html` and `md2pdf` and set `fig_ext` for both:
+You can also set format specific options. Here is how to set different `out_path` for `md2html` and `md2pdf` and set `fig_ext` for both:
 
 ```
 ---