docs: fix typos [ci skip]

README.md

@@ -58,7 +58,7 @@ as well:
 
     latexmk fduthesis.dtx
 
-If you want to get all components of `fduthesis`, please excute the
+If you want to get all components of `fduthesis`, please execute the
 following commands:
 
     xetex fduthesis.dtx

source/fduthesis.dtx

@@ -103,7 +103,7 @@ as well:
 
     latexmk fduthesis.dtx
 
-If you want to get all components of `fduthesis`, please excute the
+If you want to get all components of `fduthesis`, please execute the
 following commands:
 
     xetex fduthesis.dtx
@@ -470,8 +470,8 @@ version.
 %^^A! \LaTeX{} code will have a blue line on their left, while for
 %^^A! command lines there will be a pink line. The options, commands
 %^^A! and environments in \cls{fduthesis} will be surrounded by two
-%^^A! horizontal lines. Their usages and desciptions are provided at
-%^^A! the sametime.
+%^^A! horizontal lines. Their usages and descriptions are provided
+%^^A! at the sametime.
 %^^A!
 %
 % 本模板中的选项、命令或环境可以分为以下三类：
@@ -567,7 +567,7 @@ version.
 %^^A!   \centering
 %^^A!   \begin{tabular}{lp{24em}}
 %^^A!     \toprule
-%^^A!     \textbf{Files} & \textbf{Desciptions} \\
+%^^A!     \textbf{Files} & \textbf{Descriptions} \\
 %^^A!     \midrule
 %^^A!     \file{fduthesis.cls}      & Document class for Chinese thesis. \\
 %^^A!     \file{fduthesis-en.cls}   & Document class for English thesis.\\
@@ -683,7 +683,7 @@ version.
 % \begin{shellexample}[morekeywords={latexmk},emph={-xelatex}]
 %   latexmk -xelatex thesis
 % \end{shellexample}
-%^^A! In the following example, supoose your \TeX{} file is
+%^^A! In the following example, suppose your \TeX{} file is
 %^^A! \file{thesis.tex}. Use \XeLaTeX{} to compile, please execute
 %^^A! the following commands:
 %^^A! \begin{shellexample}[morekeywords={xelatex}]
@@ -756,7 +756,7 @@ version.
 % \end{function}
 %^^A! \begin{function}{oneside,twoside}
 %^^A!   Specifies whether single or double sided output should be
-%^^A!   generated. \opt{twoside} will be choosed by default. These
+%^^A!   generated. \opt{twoside} will be chosen by default. These
 %^^A!   option will change where the new chapters begin and how
 %^^A!   the headers display. The option \opt{twoside} does
 %^^A!   \emph{not} tell the printer to actually make a two-sided
@@ -858,7 +858,7 @@ version.
 %^^A! {\meta{value}} and in some cases \meta{value} can be omitted.
 %^^A! For the same option, the values given later will override the
 %^^A! the previous ones. Default values are indicated as
-%^^A! \textbf{boldface} in the following desciptions.
+%^^A! \textbf{boldface} in the following descriptions.
 %^^A!
 %
 % \cs{fdusetup} 采用 \LaTeX3 风格的键值设置，支持不同类型以及多种