README: use beta LaTeX symbole (#40)

* README: use beta LaTeX symbole

* README: add more beta LaTeX symbols

Co-authored-by: DavidDiazGuerra <[email protected]>

README.md

@@ -50,7 +50,7 @@ Room Impulse Responses (RIRs) simulation using the Image Source Method (ISM). Fo
 * **room_sz** : *array_like with 3 elements.*
         Size of the room (in meters).
 * **beta** : *array_like with 6 elements.*
-        Reflection coefficients of the walls as $[beta_{x0}, beta_{x1}, beta_{y0}, beta_{y1}, beta_{z0}, beta_{z1}]$, where $beta_{x0}$ and $beta_{x1}$ are the reflection coefficents of the walls orthogonal to the x axis at x=0 and x=room_sz[0], respectively.
+        Reflection coefficients of the walls as $[\beta_{x0}, \beta_{x1}, \beta_{y0}, \beta_{y1}, \beta_{z0}, \beta_{z1}]$, where $\beta_{x0}$ and $\beta_{x1}$ are the reflection coefficents of the walls orthogonal to the x axis at x=0 and x=room_sz[0], respectively.
 * **pos_src**, **pos_rcv** : *ndarray with 2 dimensions and 3 columns.*
         Position of the sources and the receivers (in meters).
 * **nb_img** : *array_like with 3 integer elements*
@@ -132,16 +132,16 @@ Estimation of the reflection coefficients needed to have the desired reverberati
 #### Parameters
 
 * **room_sz** : *3 elements list or numpy array.*
-        Size of the room (in meters). 
+        Size of the room (in meters).
 * **T60** : *float.*
-        Reverberation time of the room (seconds to reach 60dB attenuation).        
+        Reverberation time of the room (seconds to reach 60dB attenuation).
 * **abs_weights** : *array_like with 6 elements, optional.*
-        Absorption coefficient ratios of the walls (the default is [1.0]*6). 
+        Absorption coefficient ratios of the walls (the default is [1.0]*6).
 
 #### Returns
 
 *ndarray with 6 elements.*
-        Reflection coefficients of the walls as $[beta_{x0}, beta_{x1}, beta_{y0}, beta_{y1}, beta_{z0}, beta_{z1}]$, where $beta_{x0}$ and $beta_{x1}$ are the reflection coefficents of the walls orthogonal to the x axis at x=0 and x=room_sz[0], respectively.
+        Reflection coefficients of the walls as $[\beta_{x0}, \beta_{x1}, \beta_{y0}, \beta_{y1}, \beta_{z0}, \beta_{z1}]$, where $\beta_{x0}$ and $\beta_{x1}$ are the reflection coefficients of the walls orthogonal to the x axis at x=0 and x=room_sz[0], respectively.
 
 ### `att2t_SabineEstimator`