Clean README, NEWS and docs (#122)

* Update README.md

* Update usage.md

* Clean README, NEWS and docs

Fixed a few typos.

[skip ci]

NEWS.md

@@ -187,7 +187,7 @@
 ### Breaking Changes
 
 * Julia 0.7 is required, support for previous versions was dropped.
-* Documentation has been movedo to
+* Documentation has been moved to
   https://juliaphysics.github.io/Measurements.jl/stable/.
 
 ## v0.5.1 (2018-07-11)

README.md

@@ -143,7 +143,7 @@ depends on really independent measurements.
 
 Most mathematical operations are instructed, by
 [operator overloading](https://en.wikipedia.org/wiki/Operator_overloading), to
-accept `Measurement` type, and uncertainty is calculated exactly using analityc
+accept `Measurement` type, and uncertainty is calculated exactly using analytic
 expressions of functions’ derivatives.
 
 In addition, it is possible to create a `Complex` measurement with
@@ -201,7 +201,7 @@ The `Measurements.jl` package is licensed under the MIT "Expat" License.  The
 original author is Mosè Giordano.
 
 Please, cite the paper Giordano 2016 (http://arxiv.org/abs/1610.08716) if you
-employ this package in your research work.  For your convience, a BibTeX entry
+employ this package in your research work.  For your convenience, a BibTeX entry
 is provided in the [`CITATION.bib`](CITATION.bib) file.
 
 

docs/src/appendix.md

@@ -221,7 +221,7 @@ y}\right)_{y = \bar{y}} \sigma_y \right)^2 + \left(
 z}\right)_{z = \bar{z}} \sigma_z \right)^2
 ```
 
-What `Measurements.jl` really does is to calulate the derivatives like
+What `Measurements.jl` really does is to calculate the derivatives like
 ``\partial a/\partial x`` and ``\partial G/\partial x = (\partial G/\partial
 a)(\partial a/\partial x) + (\partial G/\partial b)(\partial b/\partial x)``,
 and store them in the `der` field of ``a`` and ``G`` respectively in order to be
@@ -277,5 +277,5 @@ Instead, the method for subtraction operation is defined as follows:
 
 Thus, in order to support `Measurement` argument(s) for a new mathematical
 operation you have to calculate the result of the operation, the partial
-derivatives of the functon with respect to all arguments and then pass this
+derivatives of the function with respect to all arguments and then pass this
 information to `Measurements.result` function.

docs/src/index.md

@@ -79,7 +79,7 @@ The method used to handle functional correlation is described in this paper:
   [2016arXiv161008716G](http://adsabs.harvard.edu/abs/2016arXiv161008716G))
 
 If you use use this package for your research, please cite it.  For your
-convience, a BibTeX entry is provided in the
+convenience, a BibTeX entry is provided in the
 [`CITATION.bib`](https://github.com/JuliaPhysics/Measurements.jl/blob/master/CITATION.bib)
 file.
 

docs/src/usage.md

@@ -38,7 +38,7 @@ mathematical constants. See below for further examples.
 
 Most mathematical operations are instructed, by [operator
 overloading](https://en.wikipedia.org/wiki/Operator_overloading), to accept
-`Measurement` type, and uncertainty is calculated exactly using analityc
+`Measurement` type, and uncertainty is calculated exactly using analytic
 expressions of functions' derivatives.
 
 It is also possible to create a `Complex` measurement with
@@ -77,7 +77,7 @@ Measurements.measurement(::AbstractString)
 !!! warning "Caveat about the ± sign"
     The `±` infix operator is a convenient symbol to define quantities with
     uncertainty, but can lead to unexpected results if used in elaborate
-    expressions involving many `±`s. Use parantheses where appropriate to
+    expressions involving many `±`s. Use parentheses where appropriate to
     avoid confusion. See for example the following cases:
 
     ```jldoctest
@@ -94,7 +94,7 @@ Correlation Between Variables
 -----------------------------
 
 The fact that two or more measurements are correlated means that there is some
-sort of relationship beetween them. In the context of measurements and error
+sort of relationship between them. In the context of measurements and error
 propagation theory, the term
 "[correlation](https://en.wikipedia.org/wiki/Correlation_and_dependence)" is
 very broad and can indicate different things. Among others, there may be some