correct spelling error

[ultradian]

Just submitting a spelling error in the manual. Hope I'm following correct procedure.

[codecov]

Codecov Report

Merging #150 into master will increase coverage by 3.62%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #150      +/-   ##
==========================================
+ Coverage   93.55%   97.17%   +3.62%     
==========================================
  Files           7        7              
  Lines         760      886     +126     
==========================================
+ Hits          711      861     +150     
+ Misses         49       25      -24     

Impacted Files	Coverage Δ
src/EzXML.jl	100.00% <0.00%> (ø)
src/buffer.jl	100.00% <0.00%> (ø)
src/error.jl	96.96% <0.00%> (+0.41%)	⬆️
src/xpath.jl	96.00% <0.00%> (+0.76%)	⬆️
src/document.jl	95.73% <0.00%> (+0.84%)	⬆️
src/streamreader.jl	92.99% <0.00%> (+3.06%)	⬆️
src/node.jl	99.15% <0.00%> (+5.21%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 501c2a6...2522200. Read the comment docs.